In your posted message you say the following:
She married Elias Murphy on 23 Sept 1847 in Bienville Parish, Louisiana. Elias died
in Castor or Alberta, Louisiana on 04 Aug 1896.
I have an index entry from the Bienville index of marriages which is as follows:
8-Dec 1863 Elias MURPHY Laura Ann KOONCE
Did Elias remarry or is this his son?
The date you give for marriage is 1847, Bienville Parish did not come into existance until 1848.
Good luck with your research.