The CPS investigator asked if I wanted to voluntarily "out" myself, but made it clear that I didn't have to. I did it because I was worried she didn't have anyone else. She said that some CPS centers have funds for hotel rooms for mothers to go to in cases like this, but that's not available in our town.
I didn't have to get involved personally, I just chose to anyway.
I called her at her mother's house today for updates. She says the husband still has no idea it was me, she tells me he's running with the idea that it's her mother who called (and her mother's okay with that), but she's out of there and that's what counts. He's not in jail right now, but the nebulous "they" are keeping a close eye on him, and I think that they're thinking about getting a divorce case going soon. When I talked to her today, she said that she's thinking about going back to him because he's been calling her crying saying that he loves her and misses her and that he "promises" he'll be better. She's a really sweet, sympathetic woman and it's sad because she really does love her husband in spite of everything, and I think that's a big part of why she stuck with him for so long. I told her that, IMO, it's not worth the risk of trying to go back to see if it gets better.
CPS isn't allowing the children near him and said that, because the mother's an adult, she can go back, but the kids would have to stay with their grandmother or in government custody. I don't think she wants that, so I think that her obligation to her children is keeping her where she needs to be!
I'm not too worried about my family's safety because the guy doesn't know it was us, but we've got our eyes pealed and we're being careful. He may end up incarcerated soon enough anyway if they can get a definitive child-abuse case going. AND we'll actually be moving out of the neighborhood relatively soon because we can't afford our rent.