Early Morning Commute on a Subway Platform

Tall, older adolescent male teen (perhaps in high school), with his left hand (propeller like) on the upper back of his younger, smaller female sibling (perhaps elementary school), speedily navigating the subway platform during their early morning commute — presumably to school.  Gesture and body language brought to my mind, a closeness, and friendship— oftentimes teasing, but undoubtedly loving. She wore a sly smile and his expression seemed to say, if left entirely up to her, they’d be late.