OURtorah:
She needs to find a mentor, a teacher, or someone.
Maybe sit down with her and ask her if she understands why she is getting frummmer and the reason behind every new thing she is taking on. Ask her if she understands why she is doing it, ex. If she stopped watching movies, does she know why you shouldn’t watch them? And why she stopped? And the source of the assur?
When she davens, does she feel anything????
Explain to her that you would like to help her, but since your only her age [I’m guessing, right?] you do understand what you are doing and everything, but have your own questions and aren’t to that level where you can help her with hers.
Explain to her that the best help you can give her is to tell her to find a mentor or teacher and give her ideas on how to find one…..[ex. offer her to go to her favorite teacher from high school or sem or however old you people are]
Though tell her [this is only if you can do it] that you can help by being there for her, listening to her vent, and telling what you know.
Now if this girl cannot have a mentor for some reason or another. Than if you have the time and energy, maybe you could learn a little how to help her from your own mentor. Ask her how to mentor someone if she is unable to go to someone else.
Or you can offer your friend, at the worst possible case that any questions and doubts, you can ask someone in your name and tell her the answers
Good luck
edited