Family drama- help

Tamara
Ok so to try to keep this short: my sister (22) and I (25) are both pregnant with our firsts and due about a week apart. I live on my own she lived with our parents (dad and stepmom) until literally the other day. That house is a toxic environment that she doesn't need to be in (and why I don't go to visit) and the other day, she was kicked out because she asked our psycho stepmom to back off a little (she expected us both to center our pregnancies around her and her wants...another reason I didn't go around much). Well, now she's staying with me and we are giving her until the end of August for her and her bf (27, divorced with a 3yo) to figure out what to do next. He lives with his dad due to the divorce and his dad having Stage 3/4 cancer. Literally NO ONE on his side knows my sister is pregnant (don't even get me started on that!) which is pretty much leaving her side to help with everything. Only problem is, she shunned our bio mom's side for so long they don't really want much to do with her (not in a mean way) and our dad's side is so distant we don't really talk to them nor do we have a close relationship to the few that live close because of our stepmom. So...
She is now staying with my bf and I (I'm stay at home) until the end of Aug because I still need to get ready for our baby (we just moved into this house July 1st). Her bf is trying to convince his dad to let her stay there "for a few days" and ultimately he wants her to move back into my parents' so they will keep helping with half of the medical bills (my stepbrother is currently living there and is a violent drug addict). I told her to start looking into government assistance and when she talked to her bf about it he just said "we will see/I'll think about it". The more my bf and I talk about it, it seems like he's going to try to push it to where she stays past her deadline here. If I weren't pregnant and not working, I wouldn't mind. But my bf can't and won't support her and another child. He makes just enough to support our new family barely comfortly. 
She's so in love and sheltered she doesn't want to push him to open up to his people and she has pretty much NOTHING for this baby. I'm trying to give her what I can but I need stuff too. At this point she can't even really have a baby shower (no one to really invite) and the people I'm having at mine, she doesn't like half of them (our mom's side) so I'm not joining the two. 
I just don't know what to get her- like bare essentials or groups/sites to help her through this. Her bf is clearly useless in all this and only cares about how it inconveniences him. I'm at a loss but this is my baby sister and my first nephew so I want to help but I'm limited to what I can actually pay for myself. Advice?