I predict that Kate is going to lose a ton of weight prior to finale
When the show first came out, she said her contract stipulated that she'd have to lose weight during the series, and she said this was a "win-win".
Toby lost weight, but it was later revealed that he was wearing a fat suit early on.
I think they're hiding the fact that she's wearing a fat suit this season too, and in that final future scene with Rebecca dying at Kevin's house, I think we're going to see a very different Kate.