That had to be incredibly jarring to find that kit of paraphernalia. This poor girl, from everything you've said, it sounds Luke she unfortunately already has a firm grasp on what's going on and how serious it is. I don't wish that kind of stress and worry on anyone, especially a kid. I don't really have any advice other than to say just keep doing what you're doing by being a consistent and reliable presence in her life.
And I do second the counseling/medical professional suggestion. If you all can't get her there, maybe just get some advice from someone, including what do do with and how to handle it (on her end) if anything like the makeup kit happens again.
((HUGS))
