I would imagine that it is a little bit after school.  At least long enough for everyone to be able to get home, cleaned up and wind down from the events of the day.  Especially since Paulette has to get her house in order and usually had to make sure that the twins were safely out of the house.  Certainly don't think that I'm speaking for Chrystal, but I imagine that Paulette will contact people via text message or the like when she is ready for them to come over.  Please though, feel free to introduce your character!  If nothing else, just post your getting ready for the meeting, and worry about it more when Chrystal says just when the festivities actually begin.