Katharine was the daughter of David S. and Catharine (Abell) Forbes. She was last known to have resided in Fredonia, New York.

1880 US Census: Fredonia, Chautauqua, New York
David S. FORBES Self M Male W 61 NY At Home NY NY
Sarah FORBES Wife M Female W 47 NY Keeping House NY NY
Lelia FORBES Dau D Female W 27 NY At Home NY NY
Kate CUSHING Dau W Female W 32 NY At Home NY NY
Mary CUSHING GDau S Female W 8 NY School NY NY
Kate CUSHING GDau S Female W 6 NY School NY NY

1930 US Census: Fredonia, Chautauqua, New York
Cushing, Katharine L (b: 1848*)
Cushing, Marie L (b: 1873*)
Cushing, Katharine A (b: 1875*)

Sources:
1. The Genealogy of the Cushing Family (An account of the Ancestors and Descendants of Matthew Cushing, who came to America in 1638) by James Cushing, The Perrault Printing Co - Montreal, 1905. First Edition, 1877, by Lemuel Cushing, D1881 (Finished by his family)
2. 1880 US Census: Fredonia, Chautauqua, New York
3. 1930 US Census: Fredonia, Chautauqua, New York
4. History of Chautauqua County New York and Its People, Volume III, published by the American Historical Society, Inc., Boston New York Chicago, 1921
5. The Twentieth Century Biographical Dictionary of Notable Americans: Vol III

• Married: 22 Feb 1870 in Fredonia, Chautsugua, New York

1. Mary Louise Cushing b: Dec 1871 in Fredonia, Chautaugua, New York
2. Katharine Abell Cushing b: Oct 1873 in Fredonia, Chautaugua, New York