No-one enjoyed watching her in the role more than her father. He was the barrister Harry Samuels Karlin, who wrote books on trade union law and The Factories Act.
It was he who encouraged her to go on the stage. There was no acting in the family, but as soon as she started talking – rather belatedly, she says – he recognised in her a born mimic and natural actor. She still frequently slips into voices and accents when you’re talking to her: suddenly she becomes one of the Jewish shoe-sellers in Berwick Street that she used to take off in her stand-up days.
So, putting aside thoughts of a career in the law or the synagogue, she joined RADA on the same day as June Whitfield. They’ve remained lifelong friends.
During the Second World War she toured with ENSA and in 1946 she got her first TV role.
‘Then people thought doing TV was like doing fringe in Chorlton-cum-Hardy or somewhere,’ she says. ‘They’d look at you with pity. I used to say I thought it was the coming thing.
‘So I looked in the Radio Times for names of directors. TV was all live then. I rang a director called George More O’Ferrall – directors would answer the phone in those days.
‘I told him I would be coming up to Ally Pally the next day, and could I pop in and see him? He said yes.’
He gave her a part in the first TV production of Alice in Wonderland, playing The Ugly Nurse and doing baby noises.
‘I’d be playing the nurse and then turn my back in the camera to make the baby noises.’
After that she never looked back. Role followed role in TV, stage and cinema. Early on her Orthodox Jewish upbringing lead to a number of Jewish parts: Mrs Samson in The Diary of Anne Frank, for example, and she toured in Fiddler on the Roof.
It wasn’t something she sought. ‘It just happened that way,’ she says.
In a career that’s spanned almost 65 years, she’s worked with many of the all-time greats: Olivier, Thorndyke, Sellers to name but three. At the age of 83 she was filming Flashsbacks of a Fool with Daniel Craig in Capetown. But it was working with Joan Littlewood that changed her life in the theatre.
‘She legitimized what I’d always done. I couldn’t cope with being told what to do. I liked to find my own motivation. And that’s how she liked working.’
Miriam’s known for her work in the actors’ union Equity – she was on its Council – and was awarded the OBE for her union and welfare work. But you have to press her a little to talk about it, as she doesn’t like blowing her own trumpet.
‘I was the token Jewish white woman on the Afro-Asian Committee of Equity,’ she says. ‘I worked very hard to get the media to reflect the multi-racial society we live in.
‘At the beginning when I used to go to drama schools, they were nearly all white.
‘I always used to ask why there was no ethnicity there. I never really got a reply as to whether they never applied, or were thought to be no good.’
She organised a conference for writers, producers and directors and persuaded them to put a stipulation on the front of scripts that any of the parts could be played by anyone of any ethnicity.
‘Now, at RADA for example, some of the best students are black.’
She’s also worked hard to give up and coming actors a chance.
‘When I was in Torch Song Trilogy with Tony Cher, we kept hearing how good the understudies were. I suggested to the manager that we have an understudy matinee performance. So we did. Tony and I were the ushers. Now it’s a standard part of a West End contract.’
She’s still involved in the International Committee of Artists for Peace, and Equity’s charitable trust which helps artists worldwide who are victims or persecution. She campaigns for human rights in Burma and has written letters to the press protesting against British military presence in Iraq and Afghanistan.
She bemoans the fact that, due to ill-health, she’s not as active as she once was.
‘I’ve had so many parts replaced that I’m like the bionic woman,’ she says. ‘My left shoulder is twice the size that Joan Collins’s was in Dynasty.’
But her mind is as sharp as ever. She becomes passionate about politics and world affairs. She has long been an active Labour supporter – knew Harold Wilson, Neil Kinnock and Tony Benn, and a couple of years ago she met Ed Milliband at a party.
She told him he should stand for the leadership and at that time he hadn’t made up his mind.
‘As I was leaving I said to him: ‘You will stand, won’t you?’ and he said only if I’d be his campaign manager.’
She’s rejected her religious heritage and become a Humanist.
‘I believe in a certain spirituality, the best of all religious, but I do not do God. I care hugely about human beings.’
Since she left her family home in Hampstead all those years ago, she’s spent most of her life in the Marylebone and Fitzrovia area: Montagu Place, Harley Street, and Beaumont Street.
She says she only leaves places when she’s in what she calls ‘financial smelly.’
‘I never did know how to handle money – no matter how hard I worked.’
After a few years’ exile in Clapham, she moved to her present flat thirteen years ago and loves it.
‘It’s like coming home,’ she says.