Boyfriend and the Baby Mama

So my boyfriend and I have been dating on and off now. We meet three weeks after him and the mother of his child split. 6 months later we broke things off. 7 months later we started hanging out again and we almost had a child together but their were some complications. Afterwards we decided to take our relationship more serious but in between the whole thing me and his child’s mother have never hit it off. She’s very stubborn and angry all of the time. I’ve only been around his son maybe three times because of her and her problem with me. So he hasn’t really discussed with her about her son being around me more. We recently got into a big fight which brought her into it and now she’s upset with me again. How do I make amends with her so we can move forward with our lives so me and her can be more cordial? We’ve been having to work around each other’s schedule when my child and his child since she has an issue with me and we have had an altercation in the past. I’m just trying to move forward from something that happened over a year ago. So we aren’t hating each other and be the bigger person.