She's played all the big ones - Juno, Pegeen Mike, Mommo, the mother in Death of a Salesman - as well as Big Maggie herself. Despite this, modesty is a Peg Power hallmark.

Tonight she'll walk onto the stage of the Abbey for the first time ever in Garry Hynes's new production of John B. Keane's Big Maggie, not as Maggie herself but playing the part of an old woman.

"I can't think why anyone is interested in me," she says when we meet in Wynn's Hotel in Dublin. But playing in the Abbey for the first time, at a stage of life when some people can't remember what they did with their bus pass, is not the only interesting thing about her.

Raised in Carrick-on-Suir, where she still lives, she went into amateur dramatics at 14 and was soon playing the principal boy ("in spite of my big legs") and singing ballads with one of her brothers, Bobby. For Peg Power was once Peg Clancy, and it was another brother, Liam Clancy of the Clancy Brothers, who later got her into acting.

"He came back from Dublin, where he'd been living, and said he wanted to put on The Play- boy with himself as Christie and me as Pegeen Mike," she recalls. "How could I do that, I said to him, with the two lads small?"

The year was 1955, her mother stepped in and from then on neither Peg nor Carrick-on-Suir looked back. The Brewery Lane Theatre Group was formed, in a Brewery Lane building which they bought in 1976. Initially, it was a rehearsal room, but four years later it was turned into an 80-seat auditorium.

Peg Power is a trim, grey-haired woman with a welcoming smile; she looks the sort of person who runs a neat ship. You'd have to if, for all those years, you were raising four sons while coping with a burgeoning passion for acting.

"The thing about amateur dramatics is that you do everything, play every part," she says. Does she mind, I ask, that she only has a small part in the forthcoming Big Maggie when she could probably do the whole thing in her sleep? But she puts me straight. "There are no small parts in the theatre, only small actors," she insists.

The Clancys - there were nine in the family, including the famous brothers - got lots of encouragement at home. Peg's father was a bit of an opera buff and something of an entertainer himself, always up on his feet to perform at parties ("we all had to do something, and though I hated it - I was desperately shy - my mother would coax me along").

She needed no coaxing, however, to take up the offer of a job in local radio. She worked for 11 years in Clonmel with the South Tipperary station, doing everything from presenting to scripting ads - and then reading them. "With only three or four people working full-time, you had to turn your hand to anything," she says.

Then came a major breakthrough: she was asked by the newly formed Gallowglass Theatre Company to go in with them. "That was my first experience of acting professionally," she says. It was a challenging one too - away for six weeks at a time touring like the old fit-ups, money coming in only when there was a play in production. She's never had a formal training, but did find working with Gallowglass helpful.

"We had Natalie Rafal, who gave us training in the Feldenkreis method when we were doing The Chairs [by Ionesco]. It included warm-up and breathing exercises, that sort of thing. But the best thing for me is to take a deep breath and get on with it," she says. A commonsense approach which seems to epitomise her whole character. So has she never been fazed? "Well . . . " she begins. She pauses and lowers her voice as if the person concerned might be in the bar and overhear us.

"There was one person I worked with and every time he forgot his lines, he'd look you in the eye and say: `Would you say that again?' It used to frighten the life out of me." It was her agent who got her the Abbey audition, and because it was a small part, she wasn't overly worried about it. That made getting it all the better.

"I was absolutely delighted when I got it. I never thought I'd be on the stage of the Abbey one day," she says.

And now that she's there, what does she think of it all - and especially of working with Garry Hynes? Here, something kicks in and she says formally: "I'm delighted. She's such a great director. It's a great honour to be working with her."

She's been having a good time rehearsing in Dublin, going to every show that's on as well as relishing her solitude. "I don't have to cook dinner for anyone except myself. That's a great novelty," she explains. At weekends, she goes home to Carrick where her son, Colm (in amateur dramatics), lives with her husband, Tom. Her other three sons live locally and one granddaughter, Deirdre, will be appearing in Carrick's next musical. She has nine grandchildren altogether, ranging in age from four to 22 - which brings us to the question of her own age. I ask whether it's an issue. She shakes her head, then wonders should she tell me her age.

"I wonder, should I? Should an actor say that?" she says, giving nothing away. We ponder on the dilemma, thinking about others in the same boat. Not that she would ever hurt anyone by mentioning them. In the end, she decides she doesn't want her age published. "It's just that people put labels on you," she explains. Never a good thing in the acting game.

"Just say I'm an old woman. Well, that's what I am. Playing the part of an old woman," she concludes.

Big Maggie runs at the Abbey Theatre from tonight until March 17th. To book, phone 01- 878 7222.