How do you be mature enough to get your first period?

Varies: Your body decides. Some girls get their first period at 9, others at 14 and all the years in between. There is great variation. Don't worry. Your body will know when it's time.

Great question!: Your body starts with breast development then progresses through pubic and underarm hair growth to voila! a menstrual period usually by age 13. The old axiom is true here " if the apple is ripe it will fall off the tree." and the same is true for beginning menstrual cycles.

Happens naturally: This is a complex interaction between the brain, the hormone producing glands and hormonally influenced tissues & organs. It usually progresses along a normal sequence with no effort by the young woman. If there has been no nipple/breast enlargement by 13 or menses by 16 an evaluation for delayed puberty is warranted.