I wanted to write a book about female friendship, because it's a constant that goes right through to the end of our days. Over time, romantic love changes and often becomes something different, but friendship stays pretty much the same.

I wanted to write a book about female friendship, because it's a constant that goes right through to the end of our days. Over time, romantic love changes and often becomes something different, but friendship stays pretty much the same.

I knew I wanted to write about female friendship. I've got a few friends I've known since we were teenagers, who have spanned the decades, and I do find that a fascinating thing, that friendship can last that length of time.

If you'd asked me when I was younger what life would be like in my 50s, I'd probably have imagined someone like my grandmother. I'd have looked like a little old lady who went for a shampoo and set every week. But it's funny - when you get to your 50s it's not like that at all because apart from a few aches and pains, I feel like I'm in my 30s.