No freaking way was she jogging/running to there from Dupont Circle. She might have started running back, upset after Condomdidit told her, Hey babe, take a walk on the wild site, I was only kidding about leaving Thumbelina. Which isn't implausible considering the timing - Moongirl was going out of town, Gary, seeing she was all too serious, decided it was a good time to dump her.
But no runner/jogger who owns a pair of running sneakers will go out running/jogging in tennies, and wearing a backpack to boot. The red sedan took her there, or perhaps (more likely, considering she was consulting an online map) a taxicab driven by somebody who for whatever reason will not come forward (he be da killah hisself?)
FWIW, many health clubs only allow sneakers to be used that are not used on the street. The "running shoes" she left at the apt may have been the ones she used at the club and weren't usuable for the street.