it's a name.
I've known autistic children have meltdowns over the colour of the wall, the fact the window is open , the fact the window is closed, the teacher has put her hair in plaits today, the teacher has marked their work left handed, the school dinner is cold, there is no ketchup on the chips , someone's shoe lace is undone, some one has a higher mark, ....................
You help them deal with it. You don't repaint the classroom, give them a higher mark, change your name...
I've taught in special schools where every child in the class was autistic, and frequently having meltdowns for opposing reasons. one because the door is open, one because the door is closed. for example
You help them deal with it, you can't bend the entire world around them
If she is having a meltdown because she doesn't like someone's name, she has to learn to ger used to it. Or what is she going to do for the rest of her life every time she meets some one who's name she doesn't like?
You need to get real here, I am sorry, but the idea of storming into school and complaining because a TA had a name that a student doesn't like is a total non starter