J.S.
It sounds to me like the other mom just has some serious problems. Remember that hurting people hurt people. She's got a lot of unresolved pain that she doesn't know what to do with in an adult way. That being said, none of that is your problem - you have no responsibility for it. I think you've handled things appropriately and if she continues with this behavior, you shouldn't deal with her. The problem is that you will be forced to deal with her at PTA and because of your kids. I have found that the best way to deal with people like this, when I am forced into situations with them is to avoid contact when possible and when it is none obviously rude. If contact is unavoidable, I just say "Hello, how are you?" in a very pleasant way and then find the first opportunity to move on. I do not engage in any kind of conversation. I am always pleasant - never showing my displeasure. Beyond that I just put her out of my thoughts & refuse to give any more energy to her or to the situation. I think the advice you have been given in dealing with your boys is good. You can invite them, and if the mom makes it hard, you just explain to your kids that you have invited them, but for some reason they are not able to accept your invitation and you don't know why. I wouldn't discuss her with anyone else - if you need to vent, choose one friend completely removed from the situation. And then just try not to worry about what she is thinking or saying about you. What someone like this thinks or says about you is irrelevant. If someone tells you what she's saying, just respond with, "It's really too bad she feels that way." And move on. Good luck!