There's a one event (per LI*) a day limit -- that game doesn't mention -- which prob the reason.Edit: oh nevermind, I deliberately slept to the next day and just stood and waited at the farm for evening, then went straight to the tavern after 21:00. Now the event popped. Dunno why it would work this time.
Happened to me too, where I went to the bar each day (while she's there) but nothing happened, until one day it did.
*1. , Might also limit to 1 H event a day but didn't pay enough attention for this