I agree that Connie's transformation is one of the strengths of the Trilogy. The fact that Talia Shire is FFC's sister may have had something to do with her durability in the Trilogy, and all the stuff she got away with.

BTW: I doubt that Connie sneaked Kay in to see the kids. At that point in her resurrection in the family, she wouldn't risk offending Michael. It looked to me as if Kay had legal visitation rights, that Michael chose to be absent during her visitation time, and Connie was hustling Kay out because the time had elapsed and she'd come face to face with Michael.