The event is not functionally important to the game and can be considered mostly a storyline end-cap. The caliparentsdie event is never cleaned up, thus always occurs regardless of the quest. However, this only matters if the quest is not completed before that event occurs.
If you have the save before the end of the day where the problem occurred, then the simplest fix is to change the durations for events. Though durations do not update the way one may expect, so events that appear like they would execute on separate days can occur on the same day.
If it did nothing when the event was triggered, then one of the conditions was not met. The conditions are that you must have a slave with a unique identifier of 'Cali', that slave must be a virgin("vagvirgin") with loyalty greater than 50, and this event cannot trigger more than once per progress(no idea why that is there). If the event already triggered the first screen but not the second, then you will need to delete "caliproposalseen" from the "decisions" array. If Cali is away the day of the event, then it is rescheduled for 2 days later.
So far, I have not been able to reproduce this problem on my computer.