Lena shrugged, a casual ripple of new, lanky shoulders. “Growth spurt. Doctor said I might hit 5’11”.”

Pediatricians often assess a child's future height by reviewing parental heights, current Tanner stages of puberty, and sometimes bone age X-rays. Psychological and Social Dynamics

Mira looked at her sister’s face, then at her own reflection in the mirror over Lena’s shoulder. She was still Mira. Still the eldest. Still fierce. Just a little closer to the ground.

The role reversal of a "little" sister being physically larger than an older sibling can lead to various social and emotional responses:

The tall younger sister story proves that family roles are defined by love, shared history, and emotional support—not by the numbers on a measuring tape. If you want to tailor this narrative further, tell me: What is the between the sisters?