From what I remember (and I usually read dialogues very thoroughly, or at least I try to
) - at least few times Lea actually offers drugs and 1 time she takes it.
- in a car after they picked the girls Lea offers it;
- when Lea asks MC to make chilly extra spicy - she offers it again to MC;
- if you're not on her route and she spends night with Alex: on the next morning she straight tells you that they both toke drugs;
- if you're on her route she takes it and also offers you as well (about this one I'm not sure on 100%, a bit blurry)
As for Danielle, I admit I'm a bit biased when it comes to her, but regardless - I don't remember any particular scene where she actually offers drugs, in fact - she never even talks about it, only Lea does.
So, unless smth happens on a route that i never played (Mia's route), you're wrong here.
Just to be clear, I am not antagonizing Lea, I agree she didn't do anything, yet, but it's only natural that some people get this drug-ish vibes, because the game kinda focuses on this Lea/Drug aspect a lot.