Helping my Niece?

-- My family are Mormon. My niece got baptized when she was 8, but it was very VERY obvious that she didn't know anything about the church, didn't care about it, and was literally only doing it for all the attention. She's 10 now and still doesn't care or know anything about the church. She's also always been a spoiled brat and everyone in my family (aside from her parents) can tell that if she keeps going down this path she's on, she'll end up in very bad situations. Based on her personality, we're worried about teen pregnancies, drugs, addictions, bad boyfriends - all that stuff. But her parents refuse to see any of that. 

-- She looks up to me though - I've known her since she was a baby and my name was her first word! She absolutely adores me. I'm SO thankful for that because maybe she'll trust me to help her when she asks and maybe I can stop her from ruining her life later on down the road. 

-- The problem is, my family doesn't see it that way. I'm an ex-Mormon Witch and my family has this constant worry that I'll lead my niece down an even worse road of sin and satan (they refuse to see that my religion doesn't involve sin or satan). So I'm worried that if she ever comes to me for help and I try and help her, my family will stop her and try to kick me out of her life, which wouldn't bode well for her. 

-- Basically, my niece may very likely go down a dark path, and I'm the positivity she looks up to - but my family sees me as an even darker path for her and if I try and help her, there's a good chance they'll get pissed and keep her away from me (which could mean they'd keep me away from my other nieces and nephews too). I love my niece and I know she could grow up to be an amazing person if only she'd realize the dark path she's on and turn away from it. 

-- I know I'm thinking about this too soon, but I really do worry about her. On a side note, no, I wouldn't teach her about Witchcraft unless she specifically asked. I don't believe in keeping information from people who want it. 

-- So what would you do in my situation?