I have an 11 year old daughter who is showing some noticeable signs of puberty (body hair and skin changes). She also seems to be developing breasts, however one side seems to be larger than the other. She has come to me concerned as one breast is very painful and has a large moveable disk shaped lump, whereas the other side is not painful and is much smaller. Is this normal as for girls this age, I have reassured her but it’s been a while since I went through puberty and honestly I can’t remember how I developed.