I just read your message dated from 2 years ago. We must be related : my grandfather (Adélard Da Sylva) had cousins with the names Gerald, Edna and Beryl (I met all three, at my grandparents' 50th wedding anniversary in 1978 - but not the other siblings you named).
Let me try to reconstruct how we're related ... I believe these three people's father was called Albert (or Alfred), and my great-grandfather (Zoel aka Joel) was his brother. Their father was Alfred (or Albert); the son moved to the States some time early in the 20th century.
So my grandfather was the direct cousin of Gerald, etc. My father still receives Holiday cards from the surviving sister - Edna, I believe. Edna and her husband (John, I think) visited my parents' house some 4 or 5 years ago, and I saw them then.
I do have some additional information about the Da Sylva family in Québec. Just e-mail me if you would like to know more. And I would like to you more about you, too, if that's allright.