Is there someone else?

It sounds like it. She is being unfair since she does not take the time to talk about how she's feeling. I've been there and I know people who have as well, and it needs to be talked about, and if she is going to complains she should stop and ask if this is something she has mentioned before or not and weather it was politely mentioned. There is NO excuses for not peacefully discussing problems with your other half. Granted it can be hard to talk but its possible and necessary.