So, are there ways you can approach things differently when she talks about your family? Do you get defensive? Chances are you view your family differently than she does. Try this, next time she talks about your family, say something like, "I understand how you might feel that way. Can you explain to me what may have happened in the past that leads you to feeling that way? Is there something that could be done to change that?" Also, try some of these things.....get her a greeting card, stick it in the microwave. Leave a post it note on the mirror in the morning saying "I hope you have a great day. See you tonight".....and then come home with dinner, maybe Chinese or something. If she does all the cleaning, etc., surprise her by cleaning one room in the house or something, put away all the shoes or coats. Do you get home before she does (if you both work)? Even if not, get a bunch of candles, light them in the bathroom, buy some body soaps and essentially draw a bath for her. Have her go in there, soak for awhile (shut the door so she can be alone).
Just try those types of things for two weeks or so. See if there are changes towards you (and changes you feel towards her) and let us know what happens. Little things that can make a lot of difference.