I've been playing this game since the 16th of August and still haven't seen Isabelle asleep in the town hall yet...is there any particular time or thing I have to do to be able to see this happen to unlock this option?? Did I miss the opportunity?
I think you have to wait 10 days from the time you receive your town development permit. I remember thinking that something was wrong with my game too because it seemed to take a long time. I would check every day and it should be unlocked soon.
Suggesting, if you are going to be checking every night why don't you in the mean time build your first PWP Then if it happens to be because of the PWP then you will have it done instead of waiting to hear it if it is so the case.