Wilman's museum career began when she returned to South Africa from England and worked as a volunteer in the Geology Department at the
South African Museum in
Cape Town. Because she did not have a formal degree and her father did not approve of her earning a salary, Wilman was unable to accept payment for her work at the museum. Nonetheless, she continued to work there in a volunteer capacity until 1902 when she was officially named an assistant in the Geology Department. While at the South African Museum, Wilman worked with
Louis Albert Péringuey. Péringuey's interest in the
San people and culture allowed her to take several research trips to the
Northern Cape and
Zimbabwe. In 1906 she undertook an important journey up to Kimberley, the
Vryburg region and further north, collecting specimens, and amassing data on
rock engravings which was the start of a project culminating nearly three decades later in her publication
Rock engravings of Griqualand West and Bechuanaland (1933), published in Cambridge. It remained the standard text on rock art in South Africa for nearly five decades. Wilman continued to study rock art, as well as the culture of the San and
Khoikhoi peoples for the rest of her life. ==Director of the McGregor Museum in Kimberley==