UGH! You are doing so well in a situation that's pretty tough. Shrugging off all that negativity is pretty hard (I've got a smaller version of that here) but keep going!
You are doing a good job and I know that you've got your head pretty firmly on your shoulders now. Keep being steadfast and consequent. She's acting like a teenager and you're the safe haven at the moment.
I hope you and the kids have a wonderful 4th and that your spouse ( I don't call someone who doesn't want to be a wife "wife") shows some consideration today.