I found Alexandre Lepine on the 1910 and 1920 census records in Arkansas. The daughter Mart was born ca 1904 in LA and Nellie was born ca 1909 in Arkansas. The family would have moved to Arkansas after 1904 and before 1909. It is strange that I don't find a 1900 census for the family. I would think that Victor and Charlotte were the siblings of Alexandre and therefore, Emile Lepine [bn ca 1850 in Belgium] would have been his father. The two census records that I found in Arkansas both have Belgium as Alexandre's birth country. Did you find a death record for Alexandre in Arkansas? Perhaps you may want to get copies of the death certificates for Victor and Emile Lepine. A town of birth in Belgium may be noted.
Victor Lepine died 8/28/1949 @76 [Acadia Parish vol. 10, page 391].
Emile Lepine died 12/30/1925 @75 [Acadia Parish vol. 36, page 15176].
These documents may be obtained at the Louisiana State Archives in Baton Rouge for $5.00 each.
On the 1920 census, Emile Lepine is shown as entering the country in 1886.
Leon Garot, Therese Garot and their daughter, Malina, are shown as having entered the country in 1884. The son, Joseph, appears to have come the following year.
I hope this helps with your research.