The uplifting, award-winning show about a girl aging four times too fast electrified New York. As it hits the UK, co-creator Jeanine Tesori talks about being inspired by the Aids crisis and all her friends who died young

Jeanine Tesori is thinking about her mother back home in the US. “She’s 95,” says the composer, “and she’s not been well. But she would look in the mirror and be like, ‘I can’t believe I’m old.’ It’s always a surprise, always. There’s an interiority about ageing, especially as women. You stay playful and you stay curious, but the world has other ideas.”

Ageing – and growing up, which is not necessarily the same thing – are a central consideration in the musical that Tesori has been rehearsing. Kimberly Akimbo, which the composer developed with David Lindsay-Abaire from his play, follows a teenage girl with a rare genetic condition that causes her to age at four times the normal rate. Its London debut stars the 66-year-old Maria Friedman as Kimberly. “And she has such a bright young energy,” says Tesori as we chat in a rough-and-ready rehearsal room in London, “that she doesn’t have to do anything to play 16.”

The writer’s former partner and her co-star Ruby Ashbourne Serkis describe the bittersweet nature of remounting his 90s play so soon after his death

• ‘We were swimming in the mind pool of Tom Stoppard!’ – actors salute the great playwright

I won’t, I promise, refer to Felicity Kendal as Tom Stoppard’s muse. “No,” she says firmly. “Not this week.” Speaking to Stoppard’s former partner and longtime leading lady is delicate in the immediate aftermath of the writer’s death. But she is previewing a revival of his Indian Ink, so he shimmers through the conversation. The way Kendal refers to Stoppard in the present tense tells its own poignant story.

Settling into a squishy brown sofa at Hampstead theatre, Kendal describes revisiting the 1995 work, developed from a 1991 radio play. “It’s a play that I always thought I’d like to go back to.” Previously starring as Flora Crewe, a provocative British poet visiting 1930s India, she now plays Eleanor Swan, Flora’s sister. We meet Eleanor in the 1980s, fending off an intrusive biographer but uncovering her sister’s rapt and nuanced relationships in India.