I'm going to have one of my friends text my anti vaxx mom about why her being an anti vaxxer is wrong
Isn't she your mother? Why not talk to her yourself?
Yes she is my real mother, but I'm going to have my friends message her because I don't have the courage to do so
Having opposing views to your parents on medical treatments isn't unexpected. You should bring this up with your parents yourself in order to keep an open line of discussion. That'll help you in the future when it comes to discussing even more difficult subjects.
But if I say something then she's not even going to listen to me.
I think if you talk to her calmly and politely, and show her the data, then she'll recognize what you have to say. It can be difficult talking with your parents about things like this, but it's important.