Should I get child support from their mother

I have guardianship of my now ex boyfriends kids (4,10,14) because he's a dumbass who is now facing 5-8 years in prison and their mother didn't want them. I didn't want them getting split up in foster care because I've been through that shit. My social worker said I could get child support from their mother. The reason I didn't at first is because their mom is bat shit crazy and I don't want to tick her off... I just like to stay as far away from that psycho as possible but my mom is saying I should. Their mother has more money than I will ever have. My mom did some light Facebook stalking on her page and their mom is vacationing to Hawaii. My mom says even if she doesn't want her kids she has the money to help so she should. She thinks it's unfair that she's vacationing to Hawaii while her kids are all in a small apartment with me. My ex never put her on child support because of his pride, but he's in jail now Soo. We aren't struggling too bad. I was able to get food stamps and now have WIC because of the 4 year old. We are kind of cramped which is why I let his oldest son have my room and his 10 year old daughter and 4 year old son share a room. Besides being cramped things aren't too bad. We have enough to get by even if it's paycheck to paycheck. I'm not gonna lie. Their mom scares me. Which is why I stay away from her psychotic ass... But if she has so much money... Maybe putting her on child support would be worth it... Idk..