Anna C. Brosnan was born in November 1888 and is found in the 1900 Federal Census of St. Petersburg, Clarion County, with her father, Patrick B., born in Ireland, and her mother Catherine, born in Pennsylvania. Anna's older siblings were John L., Leo D., and Ida M. Her younger siblings were Sarah K., Lucy S., and William B.

In the 1910 census, Anna was listed as a student nurse at St. Francis.

The father, Patrick Brosnan, was deceased by 1920, and the mother, Catherine, was living on Bennett Street, Pittsbugh, with the following children: John L., Leo D., Ida Mary, Anna C., Sarah K., Lucy S., and William J. B. - Anna C. was a general practice nurse.

"Anna K. Brosnan" is named in a 1922 history of the Pittsburgh Red Cross as a St. Francis graduate enrolled at the Pittsburgh Chapter and a nurse at the University of Pittsburgh Base Hospital No. 27 during World War I. (Her middle name must have been Catherine or Katherine, thus the "C" versus "K" middle initial.) She served with the American Expeditionary Forces during World War I, and is named in this article: Nurses Given Great Ovation By Pittsburgh.

At the time of the 1940 census, "Katherine" Brosnan, the mother, is residing at 7163 Penn Ave., Pittsburgh with daughters Ann(a), Sarah and Lucy. Anna was employed as a nurse at St. Francis Hospital.

Over the years, the Pittsburgh City Directories list Anna C. Brosnan, nurse, residing at 7163 Penn Avenue. In 1957, she was a clerk, and in 1958, no occupation was given.

Anna C. Brosnan died February 6, 1961 and she is buried with her family at St. Michael's Cemetery in Emlenton, Venango County, Pennsylvania. Her gravestone reads, "Anne C. Brosnan R.N. W.W.I. A.E.F. Base Hospital #27 Angers, France."