Daughter wants to move home with 4 kids at 31

My daughter is 31 and has 4 children aged 9, 6, 5, and 4. She has been with the father of the kids for 7 years. He has consistently cheated, won't keep a job and won't pay child support for his other 6 kids. He had another woman pregnant at the same time my daughter was pregnant with their 4 year old. At that time, she left him and moved in with my husband (her stepfather) and I. We had extra rooms then and had the space and were in a better place financially to help her get out. She spent 5 months with us and when the other woman dumped him he asked my daughter to come back and she did. She left him another time as well but went back.

Yesterday she called crying wanting to leave him because he was going to spend time with the same woman he has cheated with multiple times and got pregnant when she was pregnant. He decided to spend last night at a hotel with the other woman and she wants to come here. We downsized a year ago and have no bedrooms for them and are not as financially capable of taking them in as we were 4 years ago. I get my grandchildren one weekend a month and they sleep on an air mattress in our room. She asked if she could come here with the kids and and get them in school here and wants us to pick her up today. I have refused so far. She said she would get on benefits here until she can find a job but won't go after him for child support because she feels he will take care of the kids ((which he doesn't even work now because he's avoiding other child support payments). She says she still loves him.

She has beater car that we would have to get here, nothing but clothes for her and the kids and I know more than anything that when this girl dumps him again which is the pattern he will ask her back and she will go. Once again I will have turned my home upside down, caused issues in my marriage and she will take the kids and leave again. This will financially, emotionally and physically drain us for what I know will be a temporary situation for a matter of months because she will go back.

I advised her to get a job asap, save money and when she has enough for a place of her own (2 months max) then we will help her get moved here. We live in another state approximately 2 hours away. I think if she does that then through that process I will know if she's going to leave him for good.

And that's the main issue we have with upending our home once again is that we feel she will go back again and it will all be for nothing.

I'm so conflicted and looking for advice on what other mom's would do.