Say, What?

Yeah, things only register for the holidays for the household you're playing. I always make sure I've passed the 2am end to any holiday before switching, or else I have to hustle to fulfill everything for that new household before the time is up lol.

for a long time it would reset but I noticed in one of my recent plays that sims will remember celebrating if they checked something off the list, it might still be buggy since it's not so obvious as most people give one holiday to a family. In your case I'd say she would have needed to get something else after his proposal to check it off for her. Kind of wish it stuck with different households interacting but maybe it'll be randomly updated again. Fingers crossed.