My daughter decided to move in with me permanantly. She is 16 and she and her mother made the choice.
I am still paying her mother all of the support as they are automatically deducted 2x per month into
Her account. Though she has been here well over a month. I am not sure how to go about stopping the payment

If the deductions are ordered by your child support enforcement agency, you contact them and explain that the child now lives with you.

If it's ordered by the court, you file a motion with the court.

If the mother was awarded custody by a court, you have to go back to the court to modify the custody agreement. At the same time you apply for a modification of the support order.

First of course the daughter can not just decide. If she wants to, and both you and the mother agree, you will need to file in court to get residential custody changed and child support stopped. Of course now the mother may owe you child support.

If the mother agreed expecting this move to be "unofficial" and she would keep getting child support, she may be less willing to let the child move if she knows she may be the one paying child support now