Marnie Rome walked fully formed into a story I was writing two years ago. She was undercover, in biker boots and a black wig, but she was unquestionably Marnie. I recognised her at once. Later, I came to realise how many secrets she was hiding. And I came to realise that she owed a debt, in part at least, to my fictional heroines from page and TV. Not everyone on this list shares a character trait with Marnie Rome, but they are all women who’ve stayed in my head (and my heart) long after I’ve stopped reading and watching.