Puberty onset involves activation of the hypothalamic-pituitary-gonadal axis, according to Dr Shashank Jain, Paediatrics ICU specialist. GnRH from the hypothalamus triggers pituitary release of FSH and LH, which stimulate ovarian estrogen production. This cascade initiates breast development, growth spurts, and menarche-key milestones in female maturation driven by neuroendocrine regulation.