My child's school speech therepist has been on Facebook talking about the complaint I filled on her for changing records. Of course on FB she made me look evil. Is this breaking the law since speech is dealing with medical needs?

If she is merely complaining about YOU, no. Is she stating medical issues of the child, telling about the child's treatment, the child's illness. If she is just saying bad things about you, not really.

If what she is saying is not true, and you are harmed in a way where money can be measured, you may have a law suit.
If what she is saying is true, then as long as actual medical info is not given out.

But Print it out and go talk to the School principle or school authority.
Print it out and send a copy to the licence board for the therpist.

When you talked to the school authorities what have they said ?

Unless she is dscussing your child's diagnosis and treatment thren probably not.

I would report this to the school board.