DEAR HARRIETTE: My daughter used to have a bad habit of biting her nails down to the skin. Over the years, she has done much better, which is why it is worrying me now that she is back to this behavior. I don't know what is going on with her, but I'm sure that something is wrong. I try to get her to talk to me, but she's unwilling to open up.
She is an only child. To my knowledge, she may talk to h…