Thanks for responding, Jimbo!

Since I first posted here last August, I have found the marriage record for "my" William and his wife Mary Bridget Behan, and the baptismal records for their children. They were married March 1848 in Booterstown, Rathdown. William’s occupation is Policeman, and his father as MICHAEL Dowzard, farmer.
Interestingly, I also came across a February 1848 marriage record from Booterstown for George Dowzard (a Tailor) and Margaret Dowzard, both residing at Black Rock, both fathers deceased. The witnesses were WILLIAM DOWZARD and BRIDGET BEHAN. Perhaps George and William were brothers or cousins?
Per their marriage record, William and Mary BOTH had fathers named Michael…and yet that name does not appear anywhere, for their children? Based on my understanding of Irish naming traditions, that is uncommon. Perhaps the union of Anglican William and Catholic Mary was not well-accepted by their fathers/families or communities? Or was there perhaps an error on the wedding record?
The names of their children were: Mary Elizabeth, William Frederick, Mary Anne, Mary Francis, Jane Harriet, Harriet Frances, Edward Henry and Arthur William.
The Toronto baptismal records for their children included sponsors named Edward Dowzard, John Dowzard, Elizabeth Dowzard, and Mary Anne Ferguson. Perhaps they are siblings of William? There is a Mary Anne Dowzard Ferguson (1822-1889, died in Rathdown) that I strongly suspect is a sister to William: I am an Ancestry DNA match to some of her descendants. (Confusingly, this Mary Anne’s daughter was also Mary Anne Ferguson, lived 1855-1909, and she married an Edward Dowzard 1856-1921 who was a policeman. Perhaps they were cousins, somehow related?)
I am still sorting out the many people in the confusing Dowzard/Dowzer/Dowser/Douzard/Douzant/Dowyard family! (I have come across every possible spelling, ugh!)