SIL wore white to my wedding

I don't get along with my husband's family. He doesn't get along with his family. He's the baby in the family and his mom always made it known he was the only unplanned pregnancy. His dad had a vasectomy but somehow he still happened. He has gone on and off when it comes to talking to his family because they all suck.

His sister is a lot like his mom. A narcissist. She was mean to him as kids and is mean to him now and she makes fun of my weight and my infertility. She can be horrible.

His mom bought this tiara when his sister was younger and dreamed of her wearing it at her wedding. It was over 2 thousand dollars. She let his older brothers wives wear it and then his sister when she got married but his mom refused to let me have it for my wedding. I was hurt but oh well. She paid the 2 thousand for it so it's not my place to make her let me wear it.

We got married yesterday and I'll be honest. I didn't even have a don't wear white rule. It's not a super big deal to me but obviously don't wear something like a wedding dress.

Our day was already starting off bad because my husband's dad upset him and they were fighting and my husband almost kicked both his parents out of the wedding. As I'm getting ready my sister asked if I saw what my husband's sister was wearing and I said no. She said not only was she wearing white WEDDING DRESS! She was wearing that damn tiara. I went out to look and yes. She was in a long laced wedding dress, like this was clearly a wedding dress and had on the tiara.

My MiL was taking pictures of her and telling everyone how gorgeous she is. I went up to her and said absolutely not. She tried to play dumb like she didn't understand why I was upset. I said this is not happening. Either go home and change and get rid of the tiara or don't come back. She starts screaming and crying asking why I hate her? Dude! You showed up at my wedding in a wedding dress and a tiara that your mom has specifically only used for brides. My MIL starts screaming at me for mistreating her daughter.

My husband is now trying to see the commotion and other people are telling my SIL that her outfit is inappropriate. My husband just lets out a scream and goes to his groom area where he gets ready and locked himself in there. I had security escort my SIL and MIL out of the wedding. It honestly ruined our wedding. I couldn't enjoy my wedding because of her. Me and my husband were both miserable. We leave on our honeymoon this coming weekend and his mom has been blowing up his phone about how his bitch wife bullied his sister.