I found out it was a Chicago charter school, not a public school. She's pulling her kid out of it. I don't know if the charter schools have the same appeals process or anything, don't know much about them frankly except that they're supposed to be an alternative to the public schools and supposedly "better." iirc they are like LLCs though and they have more carte blanche to run things as they want. I suggested the ACLU thing like you said, but she just said, "I'm taking him out of that school and finding him another one." So... that's it, then, I'm afraid.
add'l info