I don't know the event you're talking about. I'd just keep following her around the house, advance 1 hour at a time till she moves to a new location, then follow her again until it triggers, the quest hints are fairly on point, remember it might be talking about after bedtime too, several of these "wait" quests trigger when they trigger. no input from you required, it might also be talking about the next "weekday" or day when a specific person is present/absent, so don't worry if it takes a few days.