Definition of "uncomplainingly"

Then she would walk for hours, and though she had often to do so, Palmer would uncomplainingly draw rein, and slacken the horses' speed to her pace.

1907, Barbara Baynton, edited by Sally Krimmer and Alan Lawson, Human Toll (Portable Australian Authors: Barbara Baynton), St Lucia: University of Queensland Press, published 1980, page 255