Strangely enough, I know her last partner (her husband) better than I know her. He was the captain of my pool league. He was married to her for 11 years. They divorced a few years ago at the urging of the guy who just married her!
The two men are friendly. My interactions with her have nearly always been when both men are present. When her ex heard the story, he said "I said a long time ago that something would happen. I know her better than anyone, and I know what she's capable of."
The ex is almost desperately needy for approval, but quite narcissistic, too. He's a very good pool player, and the entire league will tell you so, but the entire league will also say they can't stand being around him. I feel sorry for him in a way, because he cannot tolerate the least bit of independence in those he superficially cares about, and he can't get why they don't like him. His mother died recently and he isn't handling it well. He is getting ready to start therapy over it.
My personal opinion has been that the woman is still hung up on guy #1, who is also the father of her child. She barely has anything to do with the child, although she acts all lovey-dovey when the girl's around. If she didn't pawn the child off to her new husband, her ex, and the neighbors every chance she got it might be believable.
She flies into a rage at both men at every conceivable moment. She gets especially angry when she's mad at #1 and #2 won't get mad with her. When the men aren't around, she talks well of them in vague, sweeping statements. "He's got a good heart." But anytime she describes an actual action by one of them, it's filled with hateful comments. For what it's worth, if any female makes a slightly flirty remark like a new opponent who asked, "Did you miss that shot so you can watch my butt?" she will forever hate the woman and take it as a personal insult even though the woman has never met either of them and hasn't made an effort to.
I don't know about other relationships she may have had.