Olivier Gravel (Alexis Gravel - Marie-Madeleine Gravel) married Appoline Daze/D'Haze (Augustin Daze/H'Haze - Judith Gravel) on 1 August 1814 at St. Vincent-de-Paul Catholic Church in Laval, Quebec. Source: parish records of St. Vincent-de-Paul Catholic Church, Laval, Ile Jesus, Quebec; volume 5, page 57 in 1814, marriage record #10 in 1814; available on LDS FHL microfilm #1018206.
Family group #87 (Alexis Gravel and Marie-Madeleine Gravel) at Phyllis Nordstrom's web site iscorrect; however, she only shows four of this couple's fifteen children, and Olivier is one of the missing. Olivier was born and baptised on 12 December 1793 at St. Vincent-de-Paul. Source: parish records of St. Vincent-de-Paul Catholic Church, Laval, Ile Jesus, Quebec; volume 3, page 9 in 1793, unnumbered baptismal record in 1793; available on LDS FHL microfilm #1018206.
Finally, please note that the family group numbering system at Phyllis' web site changes whenever she updates and changes her web page. While #87 remains correct here, it very well could change in the future.