This child is more than likely the youngest, as she is sitting in the middle. We came to that conclusion because the seat belt is across her lap instead of at a diagonal, as it is with the side seats. Ava considers her hair, which is drawn very big, as her distinguishing feature. She also drew her eyes as empty circles, indicating that she may wear glasses.  She makes it clear that this is about her. She is the only person in the picture. There are no siblings, etc. Her expression is carefully blank. She isn’t smiling, she isn’t crying. Her mouth is a straight line, and she clearly went over it to exaggerate it. She is neither happy nor scared to ride with a seat belt, which may be important because it’s her first time outside of her car seat.