Raczka also suggests that sometimes the bond between sisters can be overly idealised in fiction as in life. “There can be a tendency to romanticise sisters, which can make you feel bad if you’re not close.” This is something playwright Chloe Moss explores in her new play, Run Sister Run, a co-production with Sheffield Theatre and touring theatre company Paines Plough, about two sisters whose lives have taken very different paths. Moss was interested in the idea of trauma, and how it can twist a relationship – “how it can unite you or drive you apart”.
The sisters in her play, Chloe and Ursula, were close once but have grown apart, and barely spoken in years. Moss was keen to explore what happens when two people with a shared past are forced in different directions; the play spans 40 years, and shifts backwards and forwards in time, exploring their memories of their childhood. “The sisters share things that only the two of them will ever understand,” Moss says. “Even if you don’t get on, that shared past is still there. You still know things that no one else will know about your childhood. So it’s especially poignant if that fractures as adults.”
Like Raczka, Moss has always enjoyed writing about female relationships, so writing about sisters was a logical leap. “It’s not that I don’t like writing complicated men, but I enjoy putting women centre stage. You don’t see enough women who aren’t attached to a man’s story. We’re overrun with that.”
Moss adds that she doesn’t have a sister herself. “I wonder whether I would have written it if I did.”
Frozen is at St James Theatre, New York, and previews from 30 October at Theatre Royal Drury Lane, London.
Run Sister Run is at The Crucible Theatre, Sheffield until 21 March and Soho Theatre from 25 March to 2 May.
If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.
And if you liked this story, sign up for the weekly bbc.com features newsletter, called The Essential List. A handpicked selection of stories from BBC Future, Culture, Worklife and Travel, delivered to your inbox every Friday.