As every parent knows, puberty is all about hormones. Somewhere between the ages of 8 and 12 for most girls, the brain sends a message to the ovaries, saying, "Hey, time to wake up and act pubertal!" The ovaries start producing estrogen, and reproductive organs, including breasts, begin to develop. The biologic purpose of breasts is to carry milk from moms to newborns, but breasts also contribute to a girl's feelings of femininity and attractiveness. (By the way, in studies of male views of female beauty, breast size ranks surprisingly far down the list of important physical attributes.)
If you have a daughter, here are the five most common questions girls have about their breasts, adapted from YOU: The Owner's Manual for Teens, the latest book from RealAge experts Mehmet Oz, MD, and Michael Roizen, MD.
What if my breasts are uneven in size or I don't like the way they look?
No one gets a perfectly matched set. But most girls' breasts are not more than one cup