Is there anything to do about my SIL?

My SIL (33) has been married to my brother(also 33) for about a decade now. They dated in high-school and we all were good until they moved out, I can count how many times I've seen her since then. She never really engages with our family, since I can remember her and her family are very tight nit to the point where when she would come over to our house she'd be in some sort of group chat with her family and not talk to us. Even when we would go over to her home she would never talk to me or my parents.

In the past I also invited her out to do things with me before they had their first child and even after but it was always a no.even in my brother and her wedding I was the only siblings left out of the wedding, her and her sisters and brother were all in the wedding and I was left out of every single function.

A couple years ago me and my younger brother got in an argument that left us not speaking for years, it's been a long journey to fix our relationship but we're a lot better, I don't know if that adds to her dislike of me but I thought it was something to include.

The reason I'm writing this is because of last night. Last night was my uncles wedding, it was the most perfect day you could of ever had for a wedding the bride and groom weren't stressed, they were happy and just a really beautiful wedding.

It really broke my heart with SIL I tried to make conversation with her but she just wasnt having it, she ignored me while talking to my cousin right next to me, fussed at her kid for playing with me, and fussed at me when I brought over hors d'oeuvres to my nephew for him and I to snack on. The worst part is, is when I went to hug her goodbye, I gave a big hug but she barely tapped me on my shoulder like she could care less.

I want to talk to my brother about this but anytime anything is brought up about his wife that's negative he gets really protective over her. Especially with us putting back our relationship i dont want to mess ot up again with my mouth but i dont know what to do. I don't even know how to approach this or fix things between me and her. I'm just done with being treated like this, any help would be greatly appreciated.