On Andrew's death registration his parents are given as Thomas Roberts and Julia Crowley, both born Ireland. Informant was son William of Sombra Ont.
1871 census Camden Bothwell
Andrew 16, Thomas 14 and Joseph 12 are still living with Julia 72, Michael 29 and Ellen 25.
1881, they are still altogether in Camden.
I don't see any marriage registrations on Ancestry.ca which would list their parents.