Hattie Valentine Prichard was born in Massachusetts in 1862. She was educated at the Elgin Academy in Illinois and received a bachelor's degree in public health. She came to California in her 20s and eventually took courses in kindergarten teaching at the state Normal School in San Jose. She taught kindergarten in public schools, and eventually she came to Portland, where she was supervisor of the public school kindergartens and principal of a training school for kindergarten teachers at St. Helen's Hall. She became involved in local settlement work, and in 1902 presented a report to a group of prominent citizens regarding the miserable conditions of poor children in the city.

In response to the report, the People's Institute was established in 1904, largely under the auspices of the First Presbyterian Church, Caroline Ladd, and her daughter, Helen Ladd Corbett. A building for the institute was built at Fourth and Burnside streets, and branches in Albina and South Portland followed. The institute was inspired by such urban settlements as Hull House in Chicago, and its activities included a kindergarten, home economics classes, boys' and girls' clubs, musical groups, a library, bathing facilities, and an employment bureau for women. A free health care dispensary for women and children, eventually located at Fourth and Jefferson streets, was started in 1907, as an outgrowth of the institute's aid to victims of the 1906 San Francisco earthquake. In 1931, the activities of the dispensary were absorbed by the University of Oregon Medical School (later Oregon Health & Science University). After this date, the People's Institute continued its involvement through the People's Institute Auxiliary of the Medical School Clinic.

Valentine Prichard continued to be involved in civic and social work. She died in Beverly Hills, California, in 1951.