Ace the Certified Pediatric Nurse (CPN) Exam 2026 – Leap into Your Nursing Adventure!

The first sign of sexual maturity in girls is the development of breast buds. This process marks the onset of puberty and is known as thelarche. Breast development typically begins between the ages of 8 and 13 and involves the growth of small amounts of breast tissue under the influence of hormones such as estrogen. This physical change can be indicative of the body's preparation for reproductive capability and is a critical marker in the Tanner stages of development, which outline the progression of physical maturation during adolescence.

In contrast, pubic hair development typically follows breast bud development and occurs during a later stage of puberty. Axillary hair appears even later, after pubic hair has begun to develop. Menarche, which is the first menstrual cycle, occurs after the initial signs of breast development and is not the first physiological change linked to sexual maturity. Recognizing breast budding as the initial physical sign helps healthcare providers assess and monitor the pubertal stage in girls effectively.