Breast development (thelarche) is typically the first sign of puberty in girls and occurs at age 8-12 in response to rising estrogen levels. Pubic hairdevelopment (pubarche) usually follows thelarche but can occur first. The onset of menses (menarche) is expected around Tanner stage 4, approximately 2-2.5 years after initial breast bud development. The average age for menarche is 12.5; however, lack of menses is considered normal at age <15 if development of secondary sex characteristics has been appropriate. In the 6 months preceding menarche, girls experience a growth spurt, a peak in growth velocity.
facial acne and pubic hair typical of normal adrenarche.
Appropriate management is to provide reassurance regarding her normal development and reevaluate if menarche does not occur by age 15.
Given that she has grown 3 cm in the past 3 months, she is likely undergoing a pubertal growth spurt, and menarche is anticipated within the next 6 months.