QuestionWhen does a girl fully develop?
The answer varies greatly between individual girls. A girl typically enters puberty between the ages of 8 and 14, but it not unheard of for a girl to begin earlier or start later. Obviously, a girl who starts early will likely finish early as well. The typical range of reaching physical maturity is between ages 12 and 19 with 15 being the average age.
However, physical maturity is not the complete answer. During your teenage years there is mental development taking place as well. A recent study has shown that your brain continues to develop through your mid-twenties even though your body's physical development finishes years earlier.