This is one of those Simpsons episodes that feels like it went by really fast. It's almost a shame that a lot of the focus was on Marge, because I think they could have gotten more mileage out of C. Carl Carlson's rise to power and loyal lackey Homer Simpson. Likewise, the resolution of the near-affair between Marge and Ned seemed to come and go so quickly.
Alex was with Kate during the conversation between Tom (back when he was only known as Mr. Friendly) and Locke, Jack, and Sawyer. Kate is hooded the whole time, but Alex talks to Michael, so Kate might have heard her voice.