WOW, a plot twist!!! Maverick biting your daughter is all the reason I would need to not take him back. Once, ok, maybe, but repeatedly??? Not even a question! As guilty as I would feel about taking him from the family, knowing now that he has bitten her, I would feel more guilty about leaving him there! If she is willing to pay the adoption fee, than she should be willing to go to the shelter and buy a dog that is not a risk of biting! Even if Mav is good to your step-children, he still has bitten in the past! Her kids are older, she may have grandkids someday, he may bite them, or a kid in the neighborhood, and then he would be put down! I agree with all the others, take him back, find him a home with NO children, someone who is patient, and good with dogs. Which, I know you would research well! Suggest to her that she takes the money she was gonna use on him, and rescue a "family" dog from a shelter. One that is good with kids, of all ages!