No and No
It is possible that parents get a stimulus payment for a child that was their dependent in 2020, but then the child gets the Recovery Rebate Credit when they file as a non-dependent for 2021.
It SEEMS like a payment is made twice for the same person, but that is the way the law was written. She gets a credit and you do not pay back the payment you received which included a portion for her.
It is all good.