The problem is how Lynn ended up explaining why it is that Gayle was not around. Rather than simply turn her into Norm from Cheers's wife Vera and keep her off camera until Connie could moan that with Gayle away at University, she has no chance at being the mother of the bride so her life is all used up and done and worthless now, she says that Gayle moved back in with the mother who supposedly vanished from the mortal plane. What this tells me is that when Connie was puffing herself up by thinking that she's the only option Greg's kids had for a mother, the two of them had been in contact with their real mother all along without the dozy, scrawny idiot who bewitched their dad and her huffy sidekick with the monster pervert idiot son being aware of it.
Okay. I know what you're gonna say. You're gonna point out that Greg might have pointed this out. That's because you've probably forgotten that Greg sees it as Priority One to keep Connie settled down. He tossed Lawrence to the curb because he panicked the shit out of Crazy Monster Woman first and was pitching for the other team second so if he knows that his kids are talking to the wife who checked out of their marriage but NOT out of being their mother, he's not going to inform the squawking idiot he wants to keep happy.