As the other poster mentions, flouride drops can cause these stains. But my daughter is 11. She also has these types of stains. She did not have them on her baby teeth. I was worried that something was wrong. But the dentist said that this happens when the child is sick, especially with a fever, when the teeth are developing and coming in. Sounds like you fit the bill. The bad thing is that even if my d whitens her teeth, it will not completely take care of it and may not make any difference. When she is older--after braces and such--she may want to get veneers to improve the way they look. When that time comes, I will let her decide. You can take her to get looked at to make sure if you are worried.