Marie Hammer-du Saar (1860–1955) was an independent Dutch ophthalmologist, the third woman to qualify as a physician in the Netherlands, and the first female medical consultant in the country.
A scholarship from the Mennonite Church allowed her to pursue her ambition despite skepticism on the part of the fund's managers doubting that a female physician could attract patients.
She had to supplement her doctor's fees with other, more traditional, paid activities such as counseling women on hygiene, nutrition and general health education.
In reviewing the decline of du Saar's private practice, van Loosbroek says,"Her status as a married woman and mother was also an obstacle to success.
An opportunity for her husband to take on a new conductor role caused the family to relocate to Bochum, Germany, a move opposed by du Saar who could not recover her medical practice there.