Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.
I think the biggest piece of advice is to be there to support them no matter what they decide to do. There will be days when they're leaving and days when they're staying, but if they know you'll always be there, then when the time comes to leave, they might be better able to, knowing you're there.