What is the most common age for a woman to go through puberty?

Onset of puberty in : girls now ranges from ages 8-13 & takes 1 ½- 6 years to complete. In the U.S., the average age of menarche, the 1st period, is 12.6 years in Caucasians, 12.1 years in African-Americans & 12.2 months in Latinas. Thelarche, development of breast buds is < age 10 in 50% & < age 8 in 14% in Caucasians & just < age 9 & a large %age < age 8 in African-Americans. Romeo & Juliet were ~ 12 years old.