its about perception. she wants to portray herself as having an active social life (which is attractive to other people, usually) and also, given that that guy goes for weeks without without calling her (dont know how far they have gone before this, sexually/emotionally though) she doesnt want to come across like she is so desperate as to be at his beck and call.
she did the right thing in that she should keep him wanting more, but the trick is to give a little at a time, and keep him keen...not slam the door shut in his face, letting their rapport go to hell. what she should have done is say that she has some informal sort of plans to join a group of friends doing something on the weekend (which makes her look social/attractive) and then ask what he had in mind (gives him a chance to express interest, initiate a date, or let him talk about his weekend) then she could arrange to maybe meet him "later on" in the night, or setup something during the week.
anyway thats how id do it
and besides, sugarplum, how can you complain about game playing when you yourself have a 2 day rule?