There are two stories about how plays come about: the true story and the story that makes sense. I'll tell you the one that makes sense first.
In 2014, I read an article in a newspaper about a woman in France who discovered, when her daughter was nine years old, that she wasn't actually her birth child. A nurse had accidentally swapped her daughter with another baby girl.
The 'what if' of the situation really stuck in my brain. What would I do if something like that happened to me? How could anyone possibly know how to react if placed in such an impossible situation?
I started doing some research around the topic and saw a statistic which said that worldwide an estimated 19,000 babies a year are accidentally switched at birth. I watched an amazing documentary about twin girls adopted from an orphanage in China by different families. One was adopted by a Norwegian family, the other by an American couple.
What interested me most about the story was how two genetically identical children were becoming very different people as a result of their environments. The Norwegian child lived in an isolated rural setting and had huge amounts of freedom; the American child spent all her time being driven from club to club and was almost always supervised.
In 2015, I surprised the hell out of myself by writing the first draft of Hanna in three days. My immediate reaction was that I had somehow cheated, that I couldn't possibly have written anything any good so quickly. Luckily, George Turvey from Papatango was brilliant and reassured me that the play had value and that I should keep going with it.
I think I now understand that the writing of Hanna came easily because it is the most autobiographical thing I've written, even though it's not about me at all. This brings me to the explanation which doesn't make sense.
In the programme notes for Jerusalem, Jez Butterworth gives a list of the numerous tiny things he had seen or heard which became the play's ingredients. The list is long and the small moments recorded in it seemingly unconnected, but for me it's the clearest description I've ever read of how plays actually come about.
So here is my list for Hanna:
When I was six, my dad, a teacher, brought the school chickens home. The baby chicks were all kept under a big red light to keep them warm. Twenty-five years later, my first child was born with jaundice and had to be placed under a big red light to make him better.
In 2009, I was chatting with a young mum who told me how negatively people had reacted to her when she got pregnant aged 18. A couple I know both have dark brown hair and they have had two red-haired children.
After I gave birth in 2007, I freaked my midwife out because I didn't want to hold my baby straight away, I just wanted to have a bath because I was so tired. A few years later, my husband's grandmother told me a story about a woman who had adopted two children and then had two babies naturally. The woman had confessed to her that although she felt bad, she didn't love the adopted children as much as her birth children.
One night, a friend of a friend, who I didn't know, kindly put me up for the night. I panicked and left the house in the middle of the night and ran home to Norwich.
Hanna is at Arcola Theatre 3-20 January, 2018 before embarking on a national tour
Videos