I'm getting married in a year and a half and wanted to keep my wedding party small (this is my second marriage) I've been with my fiance for two years but have known him for about 4 years. I've tried many times to be friends with his sister but have found it impossible. About two weeks ago she sent me text basically accusing me of reading a text she sent my fiance and told me to stay out of their business. She also posted something on facebook that was also intended as a dig towards me.....so basically she started all of this because she thought i read a text she sent to her brother which i didn't that i later found out that the text said she didn't want anything to do with being in the wedding. She basically started a fight that lasted two days between myself, her and her brother. She was so rude that my fiance said he didn't want to speak with her anymore. He has a nephew that he loves dearly and he has tried to reach out to speak to her to get to the bottom of things but now she will not speak with him. I know the wedding is a year and a half away but I feel like this is going to put a strain on things. Any suggestions of how to help him fix things? (mind you this isn't the first time she has tried doing something like this)