Sara, as a parent, I'd say that, from here on, you should stay out of it. You've alerted his mom to what's going on. She's taken out a restraining order, so there'll be some "legalities" to the situation now. If your friend isn't of consent age, his mom could even have her arrested...so let the authorities take care of it.

I'm NOT saying to not talk to your friend...I'm saying that you probably shouldn't try to contact his girlfriend.