Pretend to like my baby

So I don't trust my ex bf wife, long story short my ex got married while I was pregnant. She told me my baby should die while I was pregnant, told me I didn't deserve no help from my ex while pregnant so I didn't get any until I had my baby. She also said the baby wasn't his and other nasty stuff. Now that the baby's here she wants to see her, she told me I shouldn't hold grudges. My ex also told me while I was pregnant that he couldn't buy stuff for the baby because she got upset, yet he stays with her because she pays the bills. My ex also wanted me to abort the baby. He wants to be in her life now and I allow it but I don't trust his wife, I feel she's pretending to accept my baby. I can't keep my baby from her father but he's married to her, and he accepts he doesn't like my child. What should I do?