As for a marriage before 1846 in this area, you need to find someone with access to a library that has "Sacramental Records of the Roman Catholic Church of the Archdiocese of
New Orleans, Volumes 1 - 18 (1718 - 1829)".
If one can find an ancestor's name or variation of that name then you'd be able to contact the Archdiocese of New Orleans for a sacramental record. Which may or may not include parental information.
If in fact Francis is from the St. Bernard Parish, Louisiana area, she would have most probably been married in St. Bernard Catholic Church.http://stbernardcatholicchurch.com//index.php?option=com_con...http://www.archdiocese-no.org/archives/genealogy.php