Episcopalian boys and Catholic girls

I was doing some research, a few days ago, for the family history book I'm writing and ran across an interesting item about my wife's Glass family ancestors in the 1851 Canada Census data, which has recently become available to genealogists on the internet. I was looking for Hugh Glass who was an immigrant to Canada in the early 1800s from Ireland. He and his family had been enumerated on their farm in Vaughan Township. Hugh was described as a 45-year-old farmer who had been born in Ireland in 1806. His wife, Nancy, 43, was also born in Ireland in 1808. Hugh's religion was listed as Episcopalian, while Nancy was a Roman Catholic. They had seven children, ranging in age from 22 down to 7. All of the boys were listed as Episcopalians and all the girls were listed as Roman Catholics. Well, that's one way of dealing with the thorny issue of how to raise the children in a mixed marriage; seemingly arbitrary, but pragmatic.
BtheB