Andrew,Here is John's obit but not much information in it.
Pittsburgh Post Gazette-March 24, 1965
On Tuesday, March 23 1965, John of 306 Penn Ave. Wilkinsburg husband of the late Catherine Abbott Elliston, father of Mrs. Elizabeth Fleischauer, Mrs. Gertrude Arnold.Friends received at the United Presbyterian home for Aged, corner of Penn & Trenton Aves., Wilkinsburg.Services Thursday at 2:00 p.m.
You can find Elizabeth V. Elliston, Gertrude Meyer and Edward Meyer's marriage information at familysearch.org.The marriage information states that Katherine Abbott is their mother.
You can also find an obit in the Pittsburgh Post Gazette, June 12, 1949 for Christian Abbott it states his sister is Mrs. Katherine Elliston.