Usually if there isn't a big problem you can trigger the events 1 to 2 days later in the same location. If you still haven't triggered the event a few days later make sure you have already done the Cecilia quests, are on the correct version of the game, and finished the Talia/breeding license questline. I don't know how closely you are following the walkthrough so try out these directions and if they don't work send me a detailed list of what you have done or haven't done in the game and I will do speed run of the game to see if I can fix or find the problem.