My future sister- in -law...the racist?

So, a few years ago for Halloween when she was pregnant with my nephew she dressed up like Kim K and put her boyfriend (my husband’s brother) in a ton of her dark bronzer (essentially, black face) to look like Kanye. Thought it was appropriate and funny, and posted it on her instagram. (Of course, my husband’s brother was at fault too for agreeing to it, he’s not off the hook here either.)

Then, looking on her instagram further, she has a picture of herself at an art museum, standing in front of a picture of Harriet Tubman, with her index finger on Harriet’s nose (like she’s picking Harriet Tubman’s nose). After seeing this I became extremely angry, and then physically ill.

So, my brother-in-law decided she is the one, and they are getting married in July. At Christmas, she went up to my 6 year old daughter and asked if she would be a flower girl in the wedding. A nice gesture, but I was a little irritated that she didn’t ask me first, because I DONT WANT MY DAUGHTER PARTICIPATING IN THAT WEDDING!!

I am planning to go and put on a smile because I love my husband, but I really do not want my daughter to participate, and I do not want her picture from being in the wedding party posted on my SIL’s instagram with all of those other horrible racist pictures. I can’t have my child associated with those ignorant images, and these ignorant people.

Am I wrong? Am I too sensitive? Should I suck it up? Or, how can I get my daughter out of this mess without pissing anyone off? She hasn’t gotten a dress for her yet so there’s still time. What would you do?