I think your William Ball may be the son of James Ball and Jane (Jennie) Craig as referenced in John B. Craig's 1929 book "The Craigs of Goulbourn and North Gower". William married Sarah Bartman and had 11 children - Ellen, Anne, Elizabeth, William, John, Minnie, Rebecca, Wesley, Fred, Victoria and Eva. William's brothers and sisters were Thomas, Elizabeth, Annie, John, James and Hugh.
Jane Craig was a sister to Dorothy (Dolly) Craig who married James Fiddes (sic). The Craig family is from Monesk, County Cavan, Ireland. The first of the family left Ireland in 1834 and settled in Carleton County followed by other family members. I do not know whether the Ball family settled first in eastern Ontario or went directly to Grey County.
My line stems from Dorothy Craig (Fiddes-Fiddis). One of her children, Jane, married John Magee (place unknown) c1848. They were on the Marlborough Township census in 1851 and also probably lived for a time in North Gower Township before moving to Lot 157 in the 3rd Concesion ETSR in Artemesia Township before 1865. They eventually settled on the 8th Line of Artemesia Township near present day Lake Eugenia. Several of their descendants still live in the area.