“I have done masses of TV and radio. I had a contract with the BBC and was with the radio repertory company, so we were churning out plays. I did stage work at the Birmingham Rep, the Belgrade in Coventry, Second City First – a fringe company in Birmingham. I also did tours.”

Her Welsh heritage led to her being cast in a Welsh sitcom called “What The Hell Do You Want Lavinia?” with Ruth Madoc and Stan Stennett, as “a busty featherhead” called Desdemona.

Other roles saw her playing a temptress in Fearless Frank opposite Leonard Rossiter and the White Witch on stage in The Lion, The Witch and The Wardrobe.

“Most of my television life I was told I couldn’t be boxed. I had a director who if ever he was stuck for casting someone he would call me because he knew I could play anything.

“He told me ‘You are too versatile for your own good. No one thinks of you and thinks of one specific role’.

“I think the theatre training helps when I write. It means I can be all the characters and direct it as well.”

She has also written a number of plays under her married name, Liz Spear.

When her son Ben – who is now 30, a trained actor and who has also written his first book – was a baby, she could take him with her on tour. After he started school, she decided to return to the classroom as well and accepted a teaching post.

She still yearned to be creative and took up her childhood passion for writing, initially writing stories for her pupils’ projects.

“I was hooked! I just had this burning desire to write and once I started I couldn’t stop.”

They say we all have a book in us but Elizabeth seems to have entire library.

She took a break from the saga of the Llewellyns to dash off a historical novel, Against The Tide. Set in 1796, it is about a riding officer bent on avenging his father’s death at the hands of cutthroats. She is part way through a suspense thriller and has started Rainbows in the Clouds.

“I always have more than one project on the go. If I do hit a brick wall, which isn’t very often, I’ll switch to one of the others and then suddenly things slot into my head and I can go back to the original.

“Some of the stories never get finished and just get tossed to one side, but I find it helps.”

A New York producer has optioned a number of her screenplays and persuaded her to adapt Whispers on the Wind into a feature film.

Now though it is being pitched to the BBC and Elizabeth is hopeful, following the success of similar period drama Call the Midwife, that it will be picked up.

She is already toying with the idea of casting, though she accepts that her first choice to play Carrie’s duplicitous Aunt Netta – Catherine Zeta Jones – might be above the BBC’s pay grade.

“I rather fancy Rob Brydon as Carrie’s father, Brynley.”

But does she see a part for herself?

“I would be more than happy to play Aunt Annie, the down-to-earth, warm character part. They were always my favourites.”

* Shadows on the Moon by Elizabeth Revill, Belvedere Publishing, £8.99 Available online at Amazon.co.uk and by order from all good book retailers.