Ella,

What I found was a Rose Douglass (b.1881) (Doulass in ancestry index) married to a Cage(r) Douglass (b.1878) in the 1900 census in De Soto Parish. Here is their marriage record :

Cager Douglas Rose Pouncey 09 Feb 1899 De Soto

There is only one Pouncey family listed in the 1880 census and as you would expect there is no Rose because she was not born yet. That family seems very likely to be Rose's family. No Eliza though, mother's name was Mary.

I found Rose and Henry Jefferson in the 1910 census and 1920. In the 1900 census, Henry Jefferson is living with his parents in De Soto.

Let me know if you think this is your Rose. There are some minor descrepencies so it may not be her.