My Family Tree

In 1867, John Harkness, Lot 14, was a fence viewer. John could be the John Harkins in Lot 14 in 1868.
1871 PEI directory, Lot 14:
Harkness, Donald - farmer
Harkness, John - joiner

(the other John Harkness on PEI at this time was born in Scotland and had his children baptized in North Bedeque - he is the John Harkness in Lot 25 in 1861)

John Harkness was on the Patriotic Fund List of 1856.

On 31 Dec 1875, William Yeo purchased the property of John Harkness in Arlington, Lot 14.

Donald Harkness, son of John and Catherine (Ramsay) said he was born in Richmond Bay. Both Donald and William said their father was born in Nova Scotia, mother on the Island.

Child's Full Name Margaret Jean Harkness
Baptismal Date 13 June 1841
Officiating Clergy McGregor
Father's Name John Harkness
Church Name Presbyterian
Church Location Richmond Parish

Child's Full Name William Harkness?
Baptismal Date 11 May 1845
Officiating Clergy McGregor
Father's Name John Harkness
Church Name Presbyterian
Church Location Richmond Bay

There is this John from Nova Scotia:

Name John Harkness
Birth Date 02 Apr 1818
Birthplace St. Mary's River, Guysborough, Nova Scotia
Father's Name Matthew Harkness
Mother's Name Margaret Fisher
Citing this Record "Canada Births and Baptisms, 1661-1959," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:F2WG-HZK : 10 February 2018), John Harkness, 02 Apr 1818; citing St. Mary's River, Guysborough, Nova Scotia, 02 Apr 1818, reference item 8 p 72; FHL microfilm 1,376,195.

Mary S. Sellers and John Harkness (widower, age 57) married 1879 in Guysborough County. There was a John Harkness in the 1881 census of Nova Scotia, born about 1819, with wife Mary.