The transition to menopause is characterized by declining estradiol levels, which coincides with an increased risk of dementia in women. This temporal overlap suggests estradiol may influence brain aging and age-related neuropathology. We investigated whether reproductive events associated with estradiol exposure—namely, age at menarche and menopause—relate to brain aging. Using a validated machine learning model, we analyzed structural MRI data from 1,006 postmenopausal women. We found that earlier menarche, later menopause, and a longer reproductive span were each associated with less evident brain aging. These findings support the hypothesis that longer cumulative exposure to estradiol may have neuroprotective effects. However, the observed effects were modest, and estradiol levels were not directly measured. Further research is needed to clarify causal mechanisms and to examine the influence of additional factors, including genetic predispositions, lifestyle, and comorbidities. Future work incorporating hormone assays and more diverse samples will be critical for improving our understanding of the relationship between reproductive history, estradiol, and female brain aging.