But there has been a price to pay for creating laughter.
"When I started writing comedy for my one-woman show at the Tron, I was relaxed," she says of the early 1990s. "The second time around I felt a bit strange. By the third show I was strange - and off my head. And by the fourth time of writing the special I had burn-out.
"I was so bad my daughter took me to the doctor, who offered me herbal treatments. But I was so off my head I accused the doctor of trying to poison me. And I got in my car and drove all over England, talking like a budgie. I had lost it. It took time to find my way back."
Dennistoun-born Dorothy had always mined her own life experience to find the ridiculous moments. But that mining process was costly.
"I don't compare myself to the comedy greats, like Spike Milligan or John Cleese. But I have something in common in that I become slightly manic," she says.
"You have to be in that state to find the mad humour, because that is where the comedy lies. But if you stay in that manic state you crash and burn, and you can't write."
Dorothy has been writing again for her new touring show, which again takes her views on life and transfers it to the stage.
"Now I know how to pace myself," she says. "And I am a better writer. I find it easier to write from my own experiences and know instinctively what people can relate to."
Dorothy is altogether in a happier place these days. She looks 10 years younger than the 76 years on her birth certificate would suggest. "I have cut down the evening meal to lots of vegetables," she says. "And I have porridge for lunch. That keeps the weight down."
She adds, grinning: "I want to be a glamour doll you see. I want to die a glamour doll. I have wanted to be a glamour doll since I went to the Dennistoun Palais when I was 14.
"Back then, I told my mother I was going out to play tennis and she never noticed I was wearing high heels and a circular skirt. Either that or she was too tired to bother.
"I still love dancing and I am going back to study ballroom. And right now I'm exercising to Miranda Hart's maracattack. I think she is wonderful. And I have always loved the glamour of the dancing.
"I used to jive at the dancin' and can still do the Charleston. I do it now for my grandchildren and they think it is wonderful."
Dorothy grew up in a era when the very most females could aspire to was becoming shorthand typists. But she made the leap into showbiz, an area entirely dominated by men, first becoming a singer, a television dolly bird, and then a comedienne. But that was never enough.
She went on to become a playwright and a best-selling author … all after leaving school without as much as an 'O' level.
Along the way she brought up a family on her own, educated herself and picked up her English 'Higher'.
When the club circuit work dried up she took in lodgers. When she struggled to pay the mortgage she took on a variety of jobs.
Pride was unimportant when she became a market researcher. Pride took a back seat when she worked as a seamstress and battled to make sure her daughters attended university. And pride vanished when she fought to break back into entertainment, working small theatres, taking small parts in an attempt to re-invent herself in the eyes of the public.
In conversation, Dorothy always hits the funny bone and is prepared to laugh at herself.
"I do a routine about beauty and talk about myself without make-up. That is not a funny image, but you can't take yourself too seriously."
There are a few regrets. She wishes she had taken up painting sooner. She regrets not spending more time with her daughters.
"In many ways, when my husband died, I wish I had not gone back into the business because I would have looked after them better. That's all I'll say about that."
Dorothy says she has the energy to keep on performing. "I try to walk 40 minutes a day."
To relax she reads, watches TV, goes to the movies. "I love Sherlock," she says. "But what I really love, what helps me escape from it all, is dancin'. And Strictly Come Dancing? I could do that."
l Dorothy is at East Kilbride Village Theatre, March 20, King's Theatre, Glasgow, March 23, (with a matinee) and Gaiety Theatre, Ayr, March 25.