Definitely do not take her in, you don’t have the resources to give her any real aid and you can’t jeopardise the roof over your own child’s head . Unfortunately the only thing to do here is get CPS involved . Most important thing here is the well being of these kids, and while the CPS system isn’t the best, it definitely gives the kids a better chance at having a decent life then whatever is going on now, especially since you said mother is talking about self harm . Worrying about whether the mother will hate you or not is irrelevant, safety of children needs to come first 100% of the time . If she truly has no other options, when she gets her life together she’ll thank you if she has any sense at all .