Secondary sexual characteristics in girls:
Increase in breast size and darkening of skin of the nipples present at the tips of the breasts.
Appearance of hair in the genital area.
Appearance of hair in other areas of skin like underarms, hands, and legs.
Increase in the size of uterus and ovary.
Beginning of menstrual cycle.
More secretion of oil from the skin, which results in the appearance of pimples.