Generally a T has a contracted amount that they are paid by the insurance company. What you owe depends on your insurance if you have a co pay. Some insurance companies pay less than others so she may not get her entire fee. My old T had a few of $135 per session. I paid $25, the insurance company paid her $40 and the rest was the "provider responsibility". I assumed this provider responsibility meant they just had to be taken as a loss, but apparently not. I don't think clients should have to worry about that stuff. It's probably not unethical but it wouldn't sit well with me either.