The question asks to identify which option is not an estrogen-dependent pubertal change. Let's evaluate each option:
- Hair growth: This is primarily influenced by androgens, not estrogens. Hence, it is not estrogen-dependent.
- Menstruation: This process is primarily regulated by hormonal changes involving estrogens and progesterone. However, considering it results directly from the cyclic hormonal changes, it can be argued that menstruation itself is not solely estrogen-dependent.
- Vaginal Cornification: This process is directly influenced by estrogens, as they cause the vaginal epithelial cells to mature and cornify.
- Cervical mucus: Estrogen plays a significant role in altering the characteristics of cervical mucus, making it thin and alkaline during the fertile phase of the menstrual cycle.
Conclusion: While "Menstruation" is influenced by estrogen, it is a complex process involving multiple hormones. However, in the context of the question and the options given, menstruation involves other hormonal influences besides estrogen alone, making it the least estrogen-dependent change among the options provided.
Thus, the correct answer is Menstruation.