It’s one thing to talk about bra size with your gal pals or benign lumps with your ob-gyn, but quite another to broach the subject of breasts with your tween. “it’s normal to feel uncomfortable discussing this with your daughter,” says Marisa C. Weiss, MD, coauthor of Taking Care of Your “Girls”: A Breast Health Guide for Girls, Teens, and In-Betweens. But more than 40 percent of young girls surveyed by breastcancer.org said they want to talk to their mothers about breast development. So take a breath and use these talking points: Minor pain is normal. Tell your daughter that as breasts develop, tenderness, pain, lumps and bumps are par for the course. And assure her that breast cancer is very rare in girls. Size doesn’t matter. There is no normal breast size and no predictor of how big a girl’s breasts will become. Growth starts in early adolescence and can continue into the twenties. Symmetry is overrated. Uneven breasts are very common. Most girls will eventually even out, but no two breasts are ever exactly the same size.