in my honest opinion, ALL the parents involved shouldn't have given A CHILD that choice to begin with because of this issue, she was not old enough to make a MATURE, well educated decision on that matter and the prospects of "if divorce happens later" should've been addressed or at least talked about between you and "dad" NOT her.
personally "dad" needs to take responsibility for his actions and his commitment to HIS DAUGHTER, EVERYONE agreed, EVERYONE wanted the adoption and HE needs to treat her as his own as she LEGALLY is.
you can't take away who your mom is or your dad, and an adoption is saying just that "they are like my own, and i will treat them as such, emotionally, AND financially" he probably wouldn't mind getting out because it would mean less child support?? but even still he needs to stand by his commitment he made those many years ago.....regardless if i were you i would not allow the adoption to be reversed, you CAN order him for certain behaviours to take place when they are around him or visitation with BOTH kids can be interfered with.
oklahoma law, 13 + is old enough to decide the kind of visitation they want and who they want to live with in the court system...so sounds like if she's not 13 or if your state has that law, then everyone needs to suck it up until then...or just live with decisions
maybe next time YOU will think harder before allowing someone to adopt your child....the ONLY way i would let an adoption take place is if there is a PRENUPTUAL agreement filed in court that IF a divorce is to occur, the adopted parent WILL pay child support and treat the child as his/her own or if other kids are involved, visitation and parenting rights to ALL children can be hindered
another thing that just fries my @#@$@$ is YOU are considering allowing not 1 but TWO dad's to walk out on her?!!?!!....can you even imagine how she must be feeling...o mi god! poor kid!!!!! my dad walked out on me at 5 and didn't really come back in the picture until after i had my daughter by almost 2 years....i cried daily ALL MY LIFE...just cause she's not showing you her resentful hurting heart doesn't mean its not there, and do you REALLY think she's going to TELL you that she's hurting and feels abandoned not only by her dad but POSSIBLY her mother too for allowing her DADS to walk out on her....
you need to reconsider this....god i'd be FRIED if my ex or my dh EVER mentioned walking out on my daughter and i WOULD not allow that to happen even after an adoption
i'm sorry this has me really fired up....you need help