Puberty isn’t directly tied to age, @flo. Puberty refers to physical (and usually mental and emotional) stages of growth.
Examples:
- prepubescent = girls who have not started menstruation and not started growing breasts (and other things besides)
- pubescent = starting to grow breasts and pubic hair, starting to ovulate, onset of menstruation, etc.
- post-pubescent = essentially a young adult.
For some, puberty begins at age 8–9 and ends at age 12 or so; for others, it doesn’t begin until 11 or later.
Puberty is a developmental stage, not an exact measurement.
(similar steps for boys: beginning to grow facial and pubic hair, lowering of voice, broadening of the body. And for both sexes, growth spurts to adult height.