It gets more complicated. I found Alfred's death record in Orleans Parish. He died 3/16/1953 at age 63. I then found that his obit appeared in the "Times-Picayune". It appeared on 3/17/1953 [pg. 2 col. 6] and on 3/18/1953 [pg. 2 col. 6].
I found the 1850 Terrebonne Parish census for Etienne Ordonneau. It shows that he was born 1799 in France. His family was listed as following:
Jean 1827 [John was already married in 1860.]
Etienne 1831 [This may be Sylvanie.]
Adele 1833 [She married Jean Careau on 1/26/1852.]
Marie L. 1839 [She died 10/7/1917 in Terrebonne.]
In the Mormon records I found the following:
Alfred m. 3/23/1861 Elodie Calahan at St. Francis de Sales Catholic Church in Houma.
Alfred m. 2/20/1871 Azema Ramogosa in Chacahoula, Terrebonne Parish.
Alfred Ordonneaux m. 1/18/1892 Anne Ludivine Bourgeois at Chacahoula Church.
These must all be the same person. To complicate matters, I found an Alfred Ordonaux who was born 12/29/1889 in Labadieville, Assumption Parish. He was baptized on 1/4/1896 in Labadieville. His parents were Theophile Ordonaux and Marie Lydia Keller. This person certainly appears to be the same Alfred who was in Iberville Parish in 1920.
In the 1900 Lafourche Parish census [Ward 1], I found Theophile Ordano, age 32, born in LA 1/1868. His family was as follows:
Camille 7/1895 [male]
I haven't yet found out who Theophile's parents were. That info would probably connect him to one of Etienne's sons. At least, I would think so.
Are you in Louisiana? If so, you may want to research the books by Father Hebert. His volumes cover the Sacramental Records for Lafourche and Terrebonne Parishes.
Hope this helps.