Smelly vag

My bfs sister (one of my close friends) well her ex basically said her vagina smelled horrible and he wouldn’t touch her ever again unless she washed it and she said “girls aren’t supossed to wash their vagina because it hurts us” she also wears spandex and skinny jeans everyday u til she gets home and spandex to bed.... she’s been told to clean it but just won’t idk if I should try to tlak to her girl to girl or what pls help (she’s 15 btw)