She's crossed a line beyond teaching ineptitude into controlling and, potentially, abusive behaviour. To actively try to suppress your daughter's expression and insinuate herself into your family's affairs is beyond presumptuous and highly inappropriate for all the reasons the previous posters have mentioned. An attempt to create a communications barrier between parent and child is a classic sign of grooming children for abuse, especially when the groomer is in a position of authority over the child. The school should be just as concerned about psychological grooming as grooming for physical abuse.

If it were my son, I would remove him from Ms. T's classes immediately.

I would also want my husband with me at meetings, lest I feel inclined to throttle the witch.

Val, I'm so sorry you have to face this ordeal. FWIW, I think you've handled it well.

ETA: I would avoid the use of the word "bully" because that has connotations of impropriety between peers. Rather, I'd describe Ms. T's behaviour as predatory. She is deliberately behaving this way toward those under her power and influence. Big difference.

What is to give light must endure burning.