My 14 year old dd has stretch marks in her buttocks. She says they appeared very recently. She has never been over weight and is approx 5foot 5 inches. She has gone through a recent growth spurt… would this cause them ? They are quite red/ purple at the moment, can I get her to do anything to help reduce their appearance because we are going on holidays soon and she’s very self conscious about swim wear now because of them, TIA