It turns out that the Blondin families we were discussing were actually related.
Most of my information concerns the family of Louis Blondin and Genevieve Bernard who married at Montebello in 1821. Louis was the son of Joseph Blondin and Suzanne Schmidt/Smith. Louis and Genevieve had at least 12 children and I have information on many of them. The family lived in Plantagenet and Curran, Ontario, although some of the church records are in Montebello. I have some information on the 8 children of Joseph and Suzanne, too. (He married a second time in 1802 to Genevieve Calve at St. Eustache, Quebec.)
I noticed your earlier query regarding Marie Blondin, d/o of Jean and Euphrosine LaPlante. Unfortunately, I do not have any information on this couple and cannot at this time connect them to my Blondin family. They do not appear in the baptisms at St. Luc Curran or the marriage repertoire of Prescott County.