This is terrible. I wouldn't allow my dog anywhere near her.
My groomer has a closed off room with glass so you can watch him. He only handles one dog at a time and crates them before leaving or getting another dog. I've seen him need to stop what he's doing a few times and he always secures the dog in a crate before leaving the room.
When he's working on my dog I stand there and stare at the back of his head.
Call your groomer and let her know. If she does care then it'll be good feedback. If she doesn't care, then it's her loss.