DEAR ABBY: How do you tell a young girl about sex, and what's the best way to go about telling her? My niece is 12 and hasn't had her first period yet. But she has a serious crush on an older boy, and kids grow up real fast in our neighborhood. You'd be shocked if you knew how young they are when they start fooling around.

This is a difficult subject to discuss, but I know that our talk will have to happen pretty soon. She is closer to me than to her mom.

I heard you have a book about this. How can I get one?

— Almost Ready in Louisiana

DEAR ALMOST READY: Kids grow up fast all over these days — not just in your neighborhood. "The talk" with your niece should have started long ago as part of an ongoing discussion because young people are maturing earlier than they did years ago, for a variety of reasons. Because it hasn't already started happening, your niece should be told that there will be changes in her body and that they are normal. She should also be assured they are nothing to fear. You heard correctly that I publish a booklet about what teens should know about sex (and drugs). My booklet was written to help "break the ice" and begin the discussion more easily. It can be ordered by sending your name and address, plus check or money order for $7 (U.S. funds) to Dear Abby Teen Booklet, P.O. Box 447, Mount Morris, IL, 61054-0447. Shipping and handling are included in the price. It could be helpful to you if you review it before starting the discussion so you can prepare to answer her questions or guide the conversations.