Dick had informed them all that you lived in the tower before they moved in. This was more a precaution so that Jason or Rachel don’t attack you when they find a stranger in the tower.
You were a vigilante, not that San Francisco needed one desperately, but you went to school there so might as well put your training to good use and beat up the criminals that are in SF.
It was morning and the tower was quiet. Gar couldn’t sleep anymore with everything that had happened and the unfamiliar bed, so he decided to see what food there was in the kitchen, not expecting much since they’d arrived yesterday.
You were in the kitchen making breakfast before you had to leave for school. Gar momentarily freezes before he remembers that Dick had told them that you’d be living in the tower with them.
Gar: “Uh… Good morning” he says, his voice tired and hair messy. His eyes fall down to your school uniform before they go to the food you were making and then back up to your face.