L.D.
My 6-year old daughter has a very different personality than I have. And, by the same token, I have a very different personality than my mother has. When I was younger, my mom would say and do things that I didn't understand and I would take it very personally and get all huffy and puffy about it or wallow away in my hurt feelings, not understanding why she just wasn't getting it. Now that I am older, I understand that my mom just had a very different perspective than I did. Her upbringing was not the same as mine and her personality was not the same either, therefore, she had a very different filter than I did as well.
I hate to say it but, I suspect that because my own daughter has a different personality than I do and the way I am raising her is different than how I was raised, one day she will not see things from my perspective either and may take things more personally than intended also. I'm trying to raise her to realize that it is better to observe without judgment first before forming snap opinions and that there are many different perspectives and truths out there, so hopefully she will give me more of a break than I gave my mom.
Anyway, I think it is good that you have figured out that your mom is introverted and you are not. I think that she is probably more introverted and reclusive than you may realize. She probably didn't call to let you know that she wasn't going to attend your daughter's event because she didn't feel comfortable letting you down like that. Sometimes people have a really hard time being truthful about voicing their wants and needs like that and what happens is that they end up hurting the people they love more than if they had just made the call and just said they couldn't make it in the first place.
Believe me when I say that they way your mother is acting is all about her and not about you at all. She's either extremely introverted or maybe she's suffering from depression (something you may want to think about also). I think that the only way that you can find healing with this is to realize that your mom just ticks differently than you do. But, I have to tell you, if I were a betting girl, I'd lay odds on the fact that you are a more attached, more involved mom because of your mother's influence. Sometimes the lessons that we learn from the things that we see that we do not like are a blessing in disguise.
Hope this helps and that you feel better soon.