Girls have wider hips than boys because of the influence of estrogen, the primary sex hormone in females. During puberty, estrogen causes the pelvis to widen, which is a crucial adaptation for childbirth. This widening provides more space for the baby to pass through the birth canal.
The widening of the hips is a natural process that happens as part of a girl's development and prepares her body for the possibility of pregnancy and childbirth.
While the widening of the hips is primarily driven by biological factors, it's important to note that body shapes and sizes vary greatly among individuals. Some girls may have naturally wider hips than others, and this doesn't necessarily mean they're more fertile or likely to have children.