Is the daughter’s current therapist corrupted?

The mother’s perspective here is a quite accurate one, that this individual is being heavily manipulated and is not a helpful influence in the way one would like to see. In a sense, the daughter will see him as an accomplice and someone who is working in opposition to her best interests. Useful therapy cannot take place under such circumstances where there is a basic lack of trust, so this is entirely wasted effort and, if anything, counterproductive. This again speaks to the need and benefit of doing a healing outreach for all parties who are in a position to influence the daughter and the outcome of this situation—it can only help to moderate things.