What to do....I hate my husband's ex and resent the daughter?

My husband and I absolutely hate his ex wife. The problem is there is a child....which is his (or so she says and he believes). He also has 2 older daughters in their 20's, generally there is only minor issues with them, however the reasons for our fighting nowadays relates to the daughter of his last ex. The daughter is 14 and trys to come across as sweet, but I think she is a spoilt brat, and a result of her nasty, vindictive ***** of a mother. I don't really want her to come here, which she doesnt often, I wouldnt actually tell my husband I dont want her here... When I know he is seeing her, I get bitchy at him and then he retaliates (of course) and we end up fighting and I then ignore him. This afternoon this happened, because he had been drinking and so became a smart **** so I just completely ignored him. We didnt speak for hours and he went to bed without saying goodnight several hours ago. In the morning I do not intend to talk to him and he is going to see his daughters.