I presume that you live in Arkansas. Is that correct? I would suggest that you first try getting a copy of Emile's death record [at the LA State Archives] which will show where he died. In 1920, he was in Crowley, but he could have been elsewhere in 1925 when he died. If you don't get any leads from the death certificate, you could contact St. Michael The Archangel Church in Crowley and St. Joseph Church in Rayne. I know that you believe that he was no longer Catholic, but you never know. You may also want to get a copy of his succession. It may mention something about his wife.
I found mention of the marriage of Alexandre and Gustavine in the "Crowley Signal", it appears to be the 1/28/1899 issue. "Marriage at the bride's father in Prairie Hayes at eleven o'clock A.M. Wednesday, Alexandre Lepine of Vermilion Parish and Miss Gustavine Garot of Acadia."
In the Acadia Parish Marriage License list for 1889, I found the following:
J. F. Gerard - groom
Catherine Garrot [sic] - bride
2/2/1889 - date
Savinian Cart - Justice of the Peace
Leon Garot - Security
Delphe Garot, Victor Garot, Leon Garot - Witnesses
Are you familiar with the book, "Daddy's Money: A Memoir of Farm and Family" by Jo McDougall & Hilary Masters? In this book Leon Joseph Garot is mentioned as the son of Belgian immigrants. I believe it was published in Arkansas. If I remember correctly, Joe Garot, Leon's son, was living in Arkansas, the same town as the Lepine family.
It is unfortunate that the French language was not preserved.