My daughter is 9 years old and developing breast. she keeps complaining about a burning sensation in her left breast. this happens once every other week. is this normal?

Young but not abnorm: Normal puberty can begin anywhere from 10 to 14, and involves some breast discomfort as the tissue grows and glands enlarge. 9 is a bit young but is becoming more common. Talk to your Pediatrician at her next well child check to discuss this issue. Take the time to explain what is happening to her and what to expect (menses). Have age appropriate supplies and be sure she knows how to use them.