I agree that a little -- hey, even more than a little -- grace goes a long way. lol I wouldn't jump to conclusions about the misery someone may have caused herself in her life because she feels hurt by some events. Everyone is different, and some people are more sensitive than others. (I'm trying hard not to jump to conclusions about the people behind some of these responses!)
The cousin was not especially tactful, and she communicated effectively how she felt about meeting the OP, even possibly for a very short time, and she didn't put any sugar on it -- not even a grain. 'Nuff said.
My opinion is that you and your cousin may be related, and you may have been in her wedding, but you do not have a relationship with her. I'd accept that and remove her from your radar screen. Some day she may suggest getting together and you can decide at that time whether you want to reconnect.