only one way: talk to her directly.  she might deny it, but Im sure she will appreciate the direct approach.  when you talk to her give her options that she can study so that she will know what to do and decide what she wants to happen with her family.

Cant you confirm and then report to the authorities.  Stuff like this should not be tolerated and reported immediately.  If you care for your BFF, then her well being should be your primary concern.

I agree with BOB... take action before it's too late!  D:

make sure before doing some actions, or better yet, have the authorities to investigate it for you instead. but it would always be best if you talk to your friend first.

Talk to her and tell her that she can trust you. Ask her if she have done something wrong at home that made her stepmother mad. Do something to help her before it's too late.

Do you believe that our second parents are our teachers? Try asking help from them. I think they can help you about your concern with your friend.

has she brought up this issue with you before? see we can never really tell unless we have any idea. it's hard to pinpoint on people.

wish i could help but as franchesca was saying, we are not sure if it's her stepmom who is been abusing her.