Why am I always getting attacked by my Family?

I moved to Onalaska, WI in May of this present Year. My Daughter and my eldest Sisters Daughter go to the same School and are both in the 3rd Grade. I discipline my Daughter a whole lot differently than my Sister does hers. My Kids are Respectful but not Perfect. Eversince I have Moved closer to my Sister her Daughter and my Daughter get into nothing but trouble together. Thats Kids for ya. Anyways it seems as if my Daughter always gets the blame for things when I know deep down inside my Daughter has never pulled this kind of crap before and you just "KNOW" your Child! So I thought it would be a good idea to send my Daughter to another School to stay away from Conflict. The Principal is bucking on this idea and wants to just seperate them. I told him its not just that but the Girls have Recess together and my Daughter isnt getting a chance to play with any other Kids. My Daughter has told me that she feels guilty for playing with other Kids because her Cousin gives her a mean look and she feels like she is betraying her. The Principal came up with the idea of seperating them at Recess as well so my Daughter can have other friends as well. The Day after that was decided my Sister told me that she thinks I dont want her around her Daughter! I told her that wasnt it. Just yesturday my Sisters friend who is on my Friends List on FB posted up something from Youtube about Gays and it had Children in the Video Swearing. The only Comment I put on there is I didnt think it was appropriate for Kids to be swearing. I then posted a Link from YouTube about One Man and One Woman Marriage as I have a right to my Opinion. I wasnt attacking anyone. Its not my place to Judge People! Then my Sister Comments about People who commit Adultry, Lie, and Swear are no better. Then my Mother Comments about how you should only be Married once and not ever get Divorced. Obviously everyone knows they are talking about me! I didnt attack anyone why am I getting attacked? Any Suggestions?