You dont see her being hit in the first scene but there is a scene where her boyfriend has just hit her and the police are having to aprehend him, theres bruises and marks on her face, could be triggering to some people. There is also a scene at around 53 minutes in where you do see her being slapped, and threatened.
Not acted upon but there is consistent attempts by the surrogate to try cheat with the husband, videos, text, in person. Almost caught a few times and the husband is trying to hide this behavior from the wife even though he is not going along with it. Later the wife more or less gives her permission for him to do anything to get her baby back, meaning cheating. (so yes and no as he doesn't until she knows and tells him to)
Kind of. She runs off with their baby to extort a relationship out of the father. (The baby isn't born yet but it isn't biologically hers) Then again disappears with the baby after born.
Around 1hour 8 minutes in. In the bath with a razor blade shown. The actual cut action or wound isn't shown but the drips into the bath are quite emotionally triggering
The cat does die.