Tick Tock
When Julian turned sixteen at the end of the summer, he got his driver's license and a rather shiny new car—who actually got a car when they turned sixteen?!—and told Izzy to stop buying herself bus passes because he could pick her up. He normally finished his classes for the day around the same time she did.
She was hesitant at first because she didn't want her very traditional, overprotective foster mom who barely let her get the bus pass find out. Truthfully, riding with him was probably safer than taking the bus because of all the creeps in the world but Letitia wouldn't see it that way.
She would think "oh no, older boy" and instantly jump to teen pregnancy. Izzy had seen the same thing happen to one of her foster sisters and did not want to go down that road.