My friend plans on running away from home HELP!?!

call her up and tell her that she can "run away" to your house. It shouldn't reduce the impact of her parents finding her missing too much and she isn't at risk from the cold or nasty people.

If she is unwilling to, or has already left then it is your responsibility, as a good friend, to make sure she is safe and doing that will involve telling her mother.

If she is scared to tell her mum then you could offer to tell her for her. If she just can't get rid of the soon to be step dad, then couldn't she ask to talk to her mum in private?

Dear One, Please tell her mother. Better alive and mad at you than dead or who knows what. You are a good friend for doing this. You never know what could happen to her out there. You could suggest for her to talk with her mother and go out to lunch or something like that so they can be alone. She doesn't have to run away and put herself in harm's way to talk with her mother. The talk with her mother is crucial for your friend though, and just continue to be her friend by listening and caring like you do. Take good care.

Tell, her mom, if her mom doesn't listen and your friend runs away, call the police. Take a picture of her right now though.

Let her stay over and have her think over it.

My good friend wanted to run away, so I told him he could stay at my house. he ended up not running away, though :)