WATERLOO Road's Pooky Quesnel smiles as she admits actors spend their lives in an almost constant state of worry.

The actress who plays Olga Fitzgerald, ex-wife of head-teacher Vaughan (Neil Pearson) in the popular BBC school life drama explains.

"It's an incredibly stressful profession," she says with a wry smile.

"When you're not employed, you are subliminally stressed, 'Oh God, I'll never get a job again!' Then twhen you are employed you worry that you're being judged as you perform because your next job depends upon it.

"And of course the really hi-octane roles, well, they really take it out of you. I just don't know how Olivia Coleman (the Broadchurch star) manages it because she plays so many. You really have to learn how to keep the stress levels down."

Pooky (real name Joanna) has her methods.

"I guess that's why I do yoga and tai chi," she says. "And I have done kick boxing in the past, which I wish I'd kept up. It's great for getting the aggression out there."

Pooky Quesnel doesn't look as though acting has been a huge stress, but then if she didn't give so much to her roles she wouldn't have been so successful, one of the most in-demand actors on British television.

They lady who grew up in Eccles, Lancashire, (she now lives in Pimlico in London) is one of television's almost omnipresents, with roles over the years from a doctor in the first series of Cardiac Arrest, to recurring drama such as EastEnders (she played Rachel Branning) was a journalist in Midsomer Murders and a spaceship captain in the Doctor Who? 2010 Christmas special.

However she didn't have to over-worry when it came to playing a teacher in Waterloo Road, set in Greenock.

The actress was as teacher in another life, her dad was a lecturer and her mother a teacher - and her sister is a head teacher.

And Pooky also had a stint as a teacher.

"I taught for a year at a grammar school in London, in order to get money to go to drama college, " she recalls.

"It was a cramming year, teaching the kids who had failed their exams and were now about to do the resits.

"And I learned to organise my thoughts so well. You had to teach these kids a novel in two weeks, and it meant I had to focus more than I had during my degree, to stuff them full of knowledge. It was great experience for me."

The lady who has five brothers and sisters also had some interesting life experience, going from Sixth Form College in Eccles to Oxford University.

But she admits the Oxford experience didn't seem likely.

"I went to a Catholic Grammar School in Salford, and it was run by nuns who were only interested in how neat your handwriting was.

"And I guess I was a bit of a rebel, a bit of a bad girl.

"So when I got really good O Level results I was gobsmacked. From there however I went to a Sixth Form college and the teachers were amazing.

"It proved to me the right teachers at the right time in life are transformational. They embraced my boisterousness.

"Before I knew it I was playing the viola in the band, painting at lunchtimes, singing in they choir. They're attitude was 'You're brilliant. Go for it!' And I'm so grateful to those teachers."

Pooky admits going to Oxford University was 'quite a shock'. "Brideshead Revisited had just been on the telly when I went to Oxford and I had this impression it would be like that, bright young things poncing around all the time.

"And I was a bit chippy. I had a perception of posh people, not being used to that many in Manchester and you judge them, not necessarily accurately.

"But you eventually find your own level, and you go round with people of a similar background."

It's been claimed by a writer that Pooky was something of an 'Oxford celebrity', the young lady almost destined to succeed. 'You could not venture very far into artistic, musical, literary or dramatic circles without hearing something of her,' he wrote.

"I don't know about that," she says modestly. "But I was in so many societies. I just had so much fun."

Why become an actor? (She also writes, having produced TV scripts for the likes of Doctors and Family Affairs.)

"Well, I didn't know what else to do," she says, laughing. "I didn't want to go into teaching but I had no idea of any other options and I just went with acting."

She adds, smiling; "If I'd known then . . . I may have become a barrister. It seems a fascinating job, you have the intellectual cut and thrust of the court room and of course it has elements of acting.

"But anyway, I applied for drama school and got in. And now I feel very privileged. I've had a great time of it."

Pooky appreciates acting because she's had a wider range of parts than most get to play. (Recently she's appeared in a film Pride, Prejudice and Zombies, a comedy spoof.)

"For a period I did play Crying Lady a lot, because my character had been beaten/raped/divorced/about to be murdered. But then came the realisation it was having a physical effect on me and it does play havoc with your body.

"You can't show pain without feeling it. The psychology of it is really interesting.

"That's why when a lot of actors play lovers they fall in love for that period. But it's completely artificial, completely constructed.

"You train your mind to think those thoughts and your body follows. But when the play finishes the lovers come unstuck." Literally.

"Yes," she says, laughing.

Does she bring her schoolteacher role home to her partner?

"No, I've learned to wipe the characters from my head once I've played them. But of course at the time you have to go totally into it to do it justice."

And does her teacher sister approve of her performance in Waterloo Road?

"Yes, and she loves the show. But the problem she has in general is with me being an actress."

She adds, laughing; "All the kids she teaches know what I do for a living. And when I was in Shameless for example, I played quite a saucy part and she did have to put up with a great deal during that time."

Pooky doesn't have many regrets about her career to date.

"Although I really regret not being a zombie yet," she says, smiling.

"But the great thing about the business is you never know what will happen next."

*Waterloo Road continues Mondays, at 8:30pm on BBC Three, followed by 10:45pm on BBC One.