I had a big falling out with my sister over three months ago. Long story in a nutshell is that she said I don't supervise my children properly and that they are badly behaved. This is not true. And she said I was a rude person and had lied about things in the past. Didn't lie about issue in question and don't think I'm rude - she didn't give any examples to back up. I didn't insult her in anyway - the falling out was about her accusing me of things and me defending myself.
Anyway, I tried to sort it out by email but that just made it worse. She stuck by what she said and didn't apologise for the things she said. We've had no contact since - we would usually have seen each other once a week or so.
Her 4 year old is having a birthday party this weekend and we were included in the general family invite. We'll go to keep a general sort of family peace and because I'm fond of my niece and want to cousins to see each other. But I am so allergic. Any advice?