During the rise of professional biology in the late nineteenth and early twentieth century, individual naturalists continued to develop private collections by modest means and often within their own homes. Despite the increasing opportunities for women to participate in the sciences, the number of women entomologists remained relatively few. The amateur entomological career of Alice Blanche Balfour, the younger sister of Arthur James Balfour, first Earl of Balfour, reveals how a confluence of personal and social factors shaped a gentlewoman's capacity to pursue her interests in natural history. This paper revises earlier images of Alice Balfour by presenting her as an accomplished amateur naturalist who balanced her avocation with the responsibility of managing the daily domestic affairs of estate.