@Anneintherain - That is a good way to look at it. If I can't resolve it, I will definitely try to shift my attitude like that and see if it helps. Thank you!
@Pyuvii - I have tried talking to her about it a bit, but she denies it all the time. If we have actual proof of her lying, she blames me, and says I must have misunderstood or misheard. For the first little while, I felt like a horrible person, because I thought I was always misunderstanding her, and that has never happened to me before with anyone. But, the more time I spent with her, and the more I got to know other people around her, I realized it wasn't me. My partner is less than thrilled with it, but he doesn't put the same value on honesty that I do. He just ignores it when she lies, whereas I have a really hard time doing that.
@Vinccenzo - Most of the time I find out through an actual source. For example, she was going somewhere once, but didn't want to have to go, and then told us her flight got cancelled, so she would have to go a different day. However, we got a call from the airline later wanting to just confirm the new flight because she had missed the first one. So, things like that. Some of the stuff comes filtered through him, and as much as I love and trust him, he has his own biases too, so I try to take those into account with second hand information.
@MeeraReed - All people have flaws, and we decide which ones we can put up with, and which ones we can't. This is something he is ok with, I guess. I could never accept that in a partner, but I have different values than him. It doesn't make me respect him less at all, although I must admit that I have asked him a few times to try to explain to me what he likes about her because the majority of things I see are things I don't think I could accept, and I really really want to try to like her.