Barbara admits, though, that Colm was rather thrown by the addition to the family. "He was fine to begin with, but when he realised the baby was here to stay, he wasn't so happy. He's starting to get used to Gabriel now, but he still has periods of being very ill-disposed towards him. We did all the right things according to the books - prepared him for the baby coming, explained the baby was in my tummy, showed him where it would live once it was born. But you can't cater for the child's feelings towards the new arrival - after all, even as a mother you can't tell how you're going to feel!"
You'd think that with two small children to look after, Barbara would have her hands full. But no sooner was Gabriel born than she was back in the recording studio making her first album in two years, "Coming Alive Again", which was released in April. She also has an exhausting schedule of tours and has been on the road all through August, and will be again in Autumn.
"I need to work; it's an important part of my life," Barbara says. "Of course, it is difficult to tour and record and look after the kids. People who say two are no more trouble than one are talking absolute rubbish. It's bound to be twice as much work. I thought, laughably, that it was tough having Colm. It's mindbogglingly tough having both Gabriel and Colm. Colm needs my attention and so does the baby - I'm always attending to one end of him or the other!" She chuckles and adds: "But I've been lucky so far. Colm has the occasional wobbler, but it's nothing like what they call the 'terrible twos.'"
Barbara Dickson's career plans aren't limited entirely to singing either: earlier this year, for example, she was on our screens as co-presenter of the BBC's "The Diet Programme". She was an inspired choice: articulate and down-to-earth, she managed to get across information about sensible eating without sounding bossy. "I'd done two series of afternoon TV shows in Scotland before I was asked to do "The Diet Programme". I really enjoyed it."
Barbara has been a vegetarian for eleven years and feels strongly about the value of good nutrition. "I was the only person involved in that programme who wasn't dieting. Like everyone else I'd been through all those extreme diets in the past, like the pineapple diet, and the yogurt and banana diet. What was so good about the BBC diet was that it told the public at large to forget fads. What's important is that if you want to get thin, you musn't eat fat and sugar. I used to eat sunflower margarine because I thought it was better for me. The series taught me it may be better for your skin, but it's just as bad for your heart as it's got just as many calories as butter."
She has no patience with diets which say "you can't mix one thing with another, or you shouldn't eat meat after four o'clock. You have to decide how to temper good eating with your lifestyle. I'd love to have a big lunch and a tiny supper, but I don't see Oliver until 8 o'clock at night, and having supper together is our way of unwinding. I don't want to sit down and have two crisp-breads when he comes home."
Although she's a vegetarian, Barbara insists she's not fanatical about a healthy lifestyle. "If Colm eats meat when we're out, I don't stop him - but I won't keep meat at home. He has a wonderful diet on the whole. Mind you, he loves chocolate. Someone gave him a piece once and he was hooked! We were on holiday in Ireland recently and the waiter asked him what sort of eggs he'd like for his breakfast. He replied 'Chocolate'!"
One topic she will admit to being passionate about is the environment. It's something she's spoken about for years, long before many of today's pop stars jumped on the bandwagon. "I've never used my popularity as a soap box, but if people ask me how I feel about things, I'll speak my mind," she says. "I think it's acceptable for artists to include social comment in their work, as long as it doesn't get in the way of what they do."
Her latest album is an example of that. One number, "Precious Cargo", which Barbara co-wrote, sounds at first as if it's in the same mould as her most popular songs, "Answer Me" and "I Know Him So Well" (which she sang with Elaine Paige). Listen more closely and you realise it's not about love but about nuclear waste. "When I say to people that the song's about pollution I can see them thinking, 'Oh dear, that sounds a bit boring'. But I hope it's quite subtle."
She adds: "I think it's fantastic that people are becoming more environmentally conscious, just fantastic. About six months ago I walked into my local supermarket and a lot of spray cans had stickers on them saying 'ozone friendly'. I was so pleased! "Once you have small children you become very concerned about whether this world is going to be worth inheriting. You wonder what conditions are going to be like for them and their children. I try to practise what I preach, and I use unleaded petrol and drive a car with a catalytic converter - it's this extraordinary device which gets rid of most of the toxic emissions."
After many years living in London, Barbara and Oliver are now planning to move out of the capital. "We've been trying to move to the country for over a year, but we haven't found the right house yet. It's quite complicated for us because we have to be within striking distance of London, as Oliver needs to go to the BBC most days. I'd love to go back to Scotland, where I was born, but it's just too far."
Barbara grew up,in Dunfermline, in Fife, daughter of a Scottish father and a Liverpudlian mother. "My mother is a good singer and my father could sing well,too."
Barbara's father died four years ago, and to her great regret he never saw any of his grandchildren, although he did live long enough to see his only daughter married. She has fond memories of her father and still laughs when she recalls his horror when she announced she wanted to become a singer.
"I was working as a civil servant and when I decided to leave, my father thought it was a disaster. I'll never forget him saying: 'But what about your pension?' I was twenty-one, and of course I couldn't have cared less about that! My mother encouraged me a great deal, though. They say that behind every performer is a stage mother, but I've got to say that I really can't remember my mother pushing me. She never lined me up for auditions, thank goodness. I find all that horrendous. If my children show any aptitude in that direction then fine, but I'll never push them."
It was in her mother's home town of Liverpool that Barbara got her first big break, in 1974, when playwright Willy Russell offered her the chance to sing all the Beatles numbers in his musical "John Paul George Ringo...And Bert". After that she had a string of hits like "Answer Me", "Another Suitcase In Another Hall" (from 'Evita'), "The Caravan Song" and "January February". In 1983 the theatre beckoned again when she took the role of Mrs Johnstone in another Willy Russell musical, "Blood Brothers". The critics were ecstatic, hailing Barbara as an actress of great talent as well as a superb singer, and she won the Society of West End Theatre Award for best actress in a musical.
"When I read that part, it just sprang off the page, and I knew exactly what kind of woman she was," says Barbara thoughtfully. "That kind of feeling is very actor's dream. I'd love to do some more acting but I need to find something as good as "Blood Brothers", and so far it hasn't come my way."
She still loves performing live on stage and has gained a reputation for playing in theatres that few stars of her calibre would bother with. The children, of course, go with her. "The band all dote on Colm. They let him play with their instruments, and they love having him around. He has such a lot of charm. Although he's fairly lively, there's a stillness about him which is very appealing. I think Gabriel is altogether much louder, more raucous. Astrologically speaking, if you believe in such things, it ties in. Colm is a Leo, and they're quite sensible, and Gabriel is a Sagittarian male, and they're expansive. He's still quite small for his age, but if he doesn't get his food he yells! There's a lot of spirit there!
Concert tours inevitably mean separation from husband Oliver, but that holds no fears for Barbara. Before her wedding she was quoted as saying: "I'm terribly scared of marriage. If I ever marry I don't want to be divorced within two years, which can easily happen in this business."
After five years of marriage she is blissfully confident about their future together and declares: "Oliver comes from a family of actors and because of his background, my status doesn't cut any ice with him. He married me for myself, and he was singularly unimpressed by my professional life. The great thing about our relationship is that he understands the temperament of actors, but he's very calm in the face of it. He's an excellent companion to someone in front of the footlights."
Her mother is also very supportive of her. "At the moment she lives in Southport, but when we move finally to the country we're going to buy her a house near us, so we can be close by. She's never had a career - I suppose you could call her a professional mother. She wants nothing more than to see her children and grandchildren prosper. She reminds me of that joke about the Jewish grandmother, whose friend asks, 'How old are your grandchildren?' And the granny replies, 'the doctor is five and the lawyer is three.'" Barbara lets out a hoot of laughter. "That's my mum!"
Her mother, who secretly longed to go on stage but never got the chance, must be delighted by Barbara's metamorphosis into one of Britain's most consistently popular singers. When she started out she looked every inch a folk singer, with long, frizzy hair and steel-rimmed glasses. Nowadays, her hair cropped short and with the benefit of contact lenses, she looks sleek and assured, the picture of a modern career woman.
Does she have any worries about her role as a high-profile working mum? Barbara looks alarmed at the thought that she might have come across as over-confident. "Of course I do! I'm completely hysterical about it, about everything! When people say to me, 'Don't you think you're trying to do too much?' I always say, 'Yes, of course I am!' I try to be Superwoman, but I'll never achieve it. I want to do all the things I do, I want to work and I want to have my children, and my husband, and my house in the country. I want it all - I'll probably fall down somewhere, but I'll go down trying!"
"Woman's Weekly", August 1989. Barbara is interviewed by Constance Craig Smith