She was there because she had a bunch of RL things to do. Sitting at one of the windows doesn't bring you into contact with many of the men who visit, but the active ones, who walk around, may sooner or later discover you. And let's face it: it's active men we need.
But such a quiet moment is always a good occasion to chat for a while and get updated about the latest events in the streets. A girl's got to keep herself informed.