When you talk with your daughter about puberty and sexual issues, don't make a big deal about it. Try to use openings to discuss what may come up when you're watching TV together, such as commercials for acne products or a show in which people are kissing.
If you believe that your daughter needs someone with whom to talk but that she is uncomfortable talking with you, find someone else who will be a good listener and source of information for her. Perhaps she has an aunt or an adult neighbor with whom she is comfortable. Or perhaps her Girl Scout leader or school counselor can help. Many times children who are shy talking about these issues do well when the discussion is held in a group setting, such as a Girl Scout meeting or a group of girls from a class at school.
Be sure that you monitor your daughter's computer use. There are many pornographic websites that a curious child could stumble across, as well as unsupervised chat rooms in which predators can take advantage of vulnerable young people such as your daughter.
If your daughter is seven or eight years old, check further into the possibility that she may have been molested. Talk with your pediatrician or the school counselor about investigating this.