I don't know if this is the same Bylow family or another one, what are you dates for these brothers Louis and Frances Bylow.
The Bylow I was researching were in Toronto until about 1850, with parents born in Quebec.
They moved to Haldimand County, Ontario and later Michigan. I don't think I have any New York connections.
I worked on this about 3 years ago, while researching the family of Isaac King, father of Hannah King Bylow.