More than 45 census records are available for the McKinley family, from both 1901 and 1911.
Sample 1901 Carleton (New Brunswick) census records about the McKinley family available from Ancestry.ca:
A McKinley family household of at least 8 members residing in the district of Carleton (New Brunswick) was recorded in 1901. The head of household, Jas McKinley, was born in New Brunswick in 1852. He identified his heritage as Irish. By 1901, at the age of 48, he had an occupation that was recorded as "Blacksmith". Jas's wife was Maggie McKinley, who was 40 years old. Maggie was born in New Brunswick in 1860. She also identified her heritage as Irish. Jas and Maggie had 6 children, 4 boys and 2 girls. In 1885 their eldest child, a boy named Adam, was born. Two years later, in 1887, when Jas was 35 years old and Maggie was 27 years old their second child, this time a daughter, who was named Bessie, was born. Then, in 1890, with their two children ages 5 years and 3 years, their third child, Jennet, was born. In 1901 another son, their fourth child and second boy, Walter, was born. With four other children in the household, their fifth child and third boy, Robert, was born in 1892. He was followed by 1 more child: their son Thomas, born in 1896. Thus, at the time of the 1901 census, this McKinley family household was filled with 6 children whose ages were 4, 8, 10, 11, 13, and 16 years.