I just found out about my friends grad party and I wasn’t invited. Her mom planned it and it seems intentional. What should I do?

So I have no idea what happened but I wasn’t invited. We never had a falling out. She seemed to really like me as her friend, but it came time for grad party invites and they were talking about it in front of me and made up 3 versions of the stories of why I wasn’t invited (didn’t have my address, accidentally left my invite on their kitchen table, etc).
I felt really hurt by this.
We seriously didn’t have a falling out or anything. I am SO confused. I’ve only been a good friend to her.
Im not sure what the root of this is. I know they think I overdress for things and I’ve modeled, in fact a guy asked me in front of her once if I’ve been a model before. I am just speculating the reason. I’m not vain in that sense so I don’t get it.

Updates
+1 y
This “friend” literally posted a pic with me months prior and put a quote on the caption about being friends. It’s weird.
I just found out about my friends grad party and I wasn’t invited. Her mom planned it and it seems intentional. What should I do?
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