Not to rain on a parade for your friend, but in my experience its near impossible for mere mortals to fight a genetic body type. And if she doesn’t lift or train already then chances are her body naturally carries wt where it does.
I would suggest just a overall fat loss. A good clean diet change will help lower overall fat percentage, and she get at the lifting, she should keep conditioning in like cardio as well. She might just like how her big legs legs when they are more cut and muscular. I don’t think her legs are that big myself, in my opinion.
Squats and deadlifts won’t make her body worse or legs bigger, if she doesn’t do them already it can only help change her muscularity. Best thing I think would be to get her excited about lifting…then things pretty much take care of themselves if you eat clean.