I'm 19 and I'm the oldest of four siblings; two sisters, 17 and 15, and a brother, 14. My 17-y/o sister is 1.68 mts tall, and my 15-y/o sister is 1.77 meters tall. This causes my 17-y/o sister to feel inferiority complex about her height, even though she is a normal height for a girl her age, maybe even a little taller than her average height. However, who does not have a normal height is my 15-y/o sister, since at her age she is a giant

Has anyone here had those kinds of complexes? Or if not related to height, with any other physical aspect.