Catharine appears in the 1900 census in McKeesport. Kathryn appears in the 1910 census also in McKeesport. Katheran appears in the 1920 census in Mifflin Twp. Cathryne appears as a widow in the 1930 census in Jefferson Twp.
I suggest getting her death certificate and obituary. Both may list her parents and the obit may have her siblings. The PA Div. of Vital Records should have her death certificate. Check with the Historical Society of Western Pennsylvania, Western Pennsylvania Genealogical Society and the Pittsburgh Family History Center to see if they help you with the obit and her burial place. The cemetery where she is buried may have something in their burial records and the church she was a member of may also have something in their records.