Baby mamma drama, HORRIBLY!?

i have been with my boyfriend for almost 2 years now and our daughter will be 1 in february(on the 14th, v-day baby! lol)...and he has 2 other kids with his ex-girlfriend and she creates so much drama it really makes me look at her as a disgusting human being. First of all he was there through everything with their first child and left her when their first son was almost a year, but still remained to help her with him and everything and once she found out we had started to talk and see each other(we were dating a while ago before she got pregnant with their first son) and she got so upset and mad that she tried her hardest to sabotage our relationship, which i understand why, she was only 18 at the time so i know she wanted her fairy tale life, but she went so far to "claim" that he was abusive and sent her to jail, with no evidence and at that time that this abuse happened was when she was pregnant with their second child. So he left her while she was pregnant with their second, so there is another reason she wanted to get him back, but anways, he had condtions and couldn't see nor talk to her and therefore couldn't see his first son and wasn't even there for his other sons birth, and this hurt him so much and i helped him through it and he is okay now and she brings so much drama it is unbelievable! She had been haring me from the time me and him broke up from the time they started to see eachother after we had broken up but I finally got her charged and was bitter about that obviously. She gets help from him and his family with food for the children, but only for the children but she claims she doesn't see anything so she doesn't believe anything so she always asks him to come over and see the kids but he won't because she is very manipulative and still wants him back even though they haven't been together for 2 years. She has also had 2 abortions so i hope people can see where this is going. Since she found out about the child we had together she has made comments about our daugther stating that, "he only had a girl to have with when she is 11 years old" and i mean this is a child and an innocent human being..come on now..and also she is very neglectful towards her own 2 children as they have almost started a fire by turning the oven up very high and the older boy cut himself breaking into a piggy bank and she dropped him repeadtly when he was a child. His family is very loving and supporting and comes from a good home and his family is very involved in the kids lives and so is he but she is bitter and mad that he isn't with her and that he is in a better place since he left her and she is obviously upset deeply about this. She has been talking about getting full custody because she feels like a soul support parent although she is on welfare and his family helps out tremendously.. and i need to know if anybody has any advice and what his rigths are as a father and how he can handle this situation because he wants it to be all about the kids but she constantly brings up the past with their relationship and so forth..so if anybody could please p along some information that would be such a big help and would be greatly appreciated!!