Are You There God? It’s Me, Margaret is an adaptation of Judy Blume’s seminal young adult novel (1970) about an 11-year-old girl who talks to God about her friends and boys and who she wants to kiss and whether she’ll ever get breasts or menstruate. (This could also be called Are You There, Margaret? It’s Me, Your Period, and I’ll Come When I’m Ready!) Not being the target demographic, I assumed I’d be bored to death but, ever the professional, I drank 12 espressos and 17 cans of Red Bull beforehand. That turned out to be wholly unnecessary. This is a wonderfully charming, warm, tender, pitch-perfect film, much better than anything else I’ve seen recently. So that’s a good outcome, even if I did jangle for days afterwards.

The film is written for the screen and directed by Kelly Freman Craig, and Margaret is played by Abby Ryder Fortson, who would have to carry the day, and does, incandescently. She portrays Margaret’s inner dilemmas with subtlety and grace in a way that is never child actory and, most importantly, always rings true. At the outset, Margaret is horrified to discover that her parents, Barbara (Rachel McAdams, also terrific) and Herb (Bennie Safdie, not given much to do) are upping the family from New York to the New Jersey suburbs. ‘Please don’t let New Jersey be horrible,’ Margaret implores God. She doesn’t want to leave her friends behind or her Jewish grandmother, Sylvia (a restrained and moving performance from Kathy Bates, who could have gone full caricature). Herb is Jewish, Barbara is Christian, and they are bringing Margaret up with no religion so that she can decide for herself who her God is, if she decides that God exists. There’s a lovely scene later on when Margaret asks her grandmother to take her to synagogue – at last! – and Sylvia moves amid the congregation, kvelling: ‘This is my granddaughter, this is my granddaughter…’. (I haven’t given anything away. She also tries church.)

Once they’ve moved, Margaret quickly makes friends with Nancy (Elle Graham), a Wasp-y queen bee, and they form a secret club with two other girls where they muse on boys they like and chant ‘we must, we must increase our bust’ while satisfying their sexual curiosity by crowding round a pilfered copy of Playboy or an anatomy book. It takes you right back to the time when you insisted on a bra before you needed one, those first games of spin the bottle, and the obsession over who has started their periods even if, from this distance, you want to knock their heads together and shout: ‘Girls, no rush! It’ll be a drag for the next 35 years!’

It’s all handled with thoughtfulness, intelligence and wit and it’s also about the adults in Margaret’s world. Will Sylvia overcome her loneliness? Can Barbara be happy as a suburban housewife? Where are Barbara’s parents in all this? (Fellas, you don’t really figure, I’m afraid.) It is occasionally sentimental, admittedly, but it’s never glib or patronising and properly captures all the fear and yearning that comes with that leap from childhood. Meanwhile – spoiler alert! – Margaret never hears back from God, not even with: ‘Are you there, Margaret? It’s me, God. Sorry it’s taken so long but I’ve been swamped.’ Rude.