How is her diet overall? Has she had any significant trauma (mental emotional or physical)?

Homeopathy can help her body rebalance, and depending on what exactly is going on various supplements can be helpful -beef organs would be my first go to to add in. Adequate fat and calorie intake for teenage girls is super important, I am not sure what or how she eats but eating too little, or highly processed or plant based can wreck hormones especially at that growth stage.