DEIRDRE DAVIS looks remarkably composed for a woman who's stuck with a disabled husband who once sang Elvis songs, (badly) and a daughter who's more of a slapper than a shoal of performing seals.

The River City actress, who plays self-destructive Eileen in the BBC soap, is at the moment playing one of the all-time tough theatre roles.

In Lee Hall's play, Cooking With Elvis, Deirdre plays a man-obsessed drunk, Mam, who's bulemic and can't get enough of toy boys and board games.

Meanwhile her daughter has also gone off the rails because her dad, played by Still Game's Gavin Mitchell, who was once an Elvis impersonator has had an accident and is now disabled.

It's fair to say the play is blacker than the black hole of Calcutta at three in the morning.

It's tough stuff. The subject matter - alcoholism, illness, promiscuity, desperation and vegetables (you have to see it) - isn't the easiest for actors to work with.

"It's a great play," says Deirdre. "I'm playing a drunk again. I seem to get cast as a drunk a lot in theatre.

"But it's a tricky part. My character has to spends the play looking at her quadroplegic husband who's a constant reminder of their bad marriage."

She adds, grinning: "It's just a snapshot of people's lives, people who are having to cope with exceptional, nightmarish circumstances."

So how does she bring Mam to life? Can she call upon personal experience?

"No, I'm not an alcoholic slut," she says, laughing."And I've never been bulemic. I hope there's nothing about this woman, who's a horror, that can be compared to me."

What Deirdre Davis can bring to a role such as this is wide life experience, a realisation that play acting is nothing compared to the drama that life can force you to take part in.

Deirdre, who grew up in Cardonald, in the South Side of Glasgow, reveals she's had her own years of character building. She spent six years trying for a baby, becoming obsessed by the notion, only to fail time and time again.

"I had remarried, to Greg and we wanted to have a child. I already had Khardine from my previous marriage, who's now 24, but we wanted a little baby.

"So it was six years of trying, of working out when periods were due, of determining fertile moments, and becoming obsessed by the idea of having a baby.

"But nothing happened and we couldn't afford IVF.

"And so I had to get myself to the point of accepting it just wasn't going to happen."

But of course life is about expecting the unexpected.

As soon as Deirdre stopped trying for a baby, she fell pregnant.

"We had just moved to a new house and that night I found myself saying to Greg and my daughter Can anyone remember when I last had a period?' And no one could. I certainly couldn't, even though I had been someone entirely consumed by my menstrual cycle. But I had let the idea of becoming pregnant go.

"So Greg drove to an all-night Asda and bought a pregnancy testing kit. And it was positive."

Fantastic! Wonderful. But Deirdre had just started River City at the time. Yet, she didn't fear that she may have blown her chances of an extended contract.

"I didn't care," she says with a shrug. "I knew it was only a job. But the producers were fantastic. And when I was in scenes to hide my size they'd give me lots of things to hold. A bail of towels was often the choice, even though I was the size of a house."

She adds; "I was a wee bit unsure if they would want me back after my time off, but they did. They were great. And I love Eileen."

Deirdre's home life was complete. She had lost a dining room in the new flat when it became a bedroom but gained a daughter - Mirabel, now six years old.

"Khardine would say; 'Everyone will think I'm the mum and you're the gran,' and I suppose she was right, even though I was tempted to slap her. But the two girls get on fantastically well together. They are sisters who gang up on me.

"But I suppose if I learned anything from the whole experience is not to take life too seriously. Try and relax and see what happens."

Davis certainly laughs a lot.

"Well, I love the job I do," she says.

"I went to drama school because I wanted to pretend to be other people. And I'm still doing that. I love playing other people because I learn more about what makes people tick. I like to observe people."

Which is rather unusual for an actress.

"Yes, actors usually want people to notice them. I am actually fairly shy. I like to sit and watch."

And then perform.

"Yes, I do need the applause. I'm not going to do a play in my bedroom to be seen only by my mum. What you don't want to hear is that there are five people in an audience.

"What you need to hear is that a play has sold out. That's when you get the biggest buzz."

She adds; "I don't get the same sort of buzz out of doing television. I love the reaction you get in theatre. It's a total ego trip."

The reaction to her drunken slut character of the moment is certainly fuelling the ego.

"Oh, yes," she agrees, excitedly.

"I love becoming a drunken slut for a couple of weeks."

The actress adds, with a wicked laugh; "Then I don't have to do it in real life." Cooking With Elvis, until July 25, the Tron Theatre.