step children

I have been with my husband for 3 years now been married for one. We have a 19 month old daughter together and I'm 28 weeks pregnant with our son. He has a 5 year old daughter with his ex and it's just hell anymore. Everything I say to her makes her cry even when I'm not yelling at her. As of right now we have joint custody so we see her every two days and every other weekend. So the schedule is we have her Monday and Tuesday her mom has her Wednesday and Thursday we get her Friday through Monday morning. Than it will change to where we have her Wednesday and Thursday. Her mother is allowed to have right to refusal since my husband works day shift. So I pick her up at 230 on our days. But she only uses it if she has her the night before. Her mother moved over an hour away 3 years ago. It's just hard to deal with a child that cries about everything and I mean everything. If it's not real tears than she is tearing up. My husband will not talk to her bc he says she has a hard life. I grew up with only one parent my dad walked out and didn't come around very often. She is very spoiled at both homes. We know her mother doesn't yell at her for anything bc she doesn't want to upset her. She hits her brother and sister. Her mom has a 3 year old son. I just don't know what to do anymore. My husband still gives in to her mom all the time. The only time he ever reAlly tries for sex is when he has seen his ex. We aren't suppose to be having sex now anyways bc I have placenta previa. I'm just so lost with this relationship anymore. Part of me wants out but the other part doesn't.