Thats the thing, I SERIOUSLY doubt she will voluntarily give up custody the second time around. The first time had more to do with the abusive realtionship tha developed with her MIL. Her MIL is a real piece of work, used the twins as weapons for YEARS in an effort to coerce her into giving into her demands. She still got to see them regularly , but signing over custody was the only clear way to end the mental torment of having visitation with held on a whim or dangled as an incentive do to her MIL's bidding.
She see's our kids as a "second chance " of sorts, of this I am CERTAIN , from both words and behavior. The irony of course being she's created the conditions with her recent choices to go through the whole thing all over again.
