Suggestion: If you have not done so yet, request a copy of her marriage license from the Rapides Parish Courthouse. The price is reasonable and at least you could confirm the name of her husband and the approximate date she lived in Rapides Parish.
I am helping a cousin research a Mitchell (spelling questionable) line who imigrated here from Syria in the early 1900's. They were in Rapides Parish in the early 1900's but later moved to DeSoto Parish. Your line may be connected.