Clara opens the door a crack, just wide enough for me to pass through the tray of popcorn and orange juice. She has invited three friends for a sleepover and the fug of teenage hormones and hair styling products in her bedroom would choke a cat.
“Thanks, Mum” she says, jerking her head meaningfully. She doesn’t quite add, “That will be all”, but the message is clear. When, a few minutes later, I bustle in with extra pillows, the girls form a...