Nation family of Upshur Co., TX or KY

My gggandmother was Mary Ethel (Nation?) m. Elijah Decker of Grayson Co., KY.  He died abt 1856 Upshur Co., TX.

Decker's widow married Capt. Charles Alexander Earp and they had two children.  She died and he married his 3rd wife (no issue).

I am looking for Mary Ethel's parents.  She was possibly Mary Ethel Nation/s.  Do not know if she married before marrying Elijah Decker.

Is any one familar with any Nation family in E. TX???

Any help on the possible parents of MEN would be appreciated.  She died 11 Aug 1858. 

Charles Alexander Earp raised MEN's 3 Decker daughters.  One was my ggrandmother, Sina/Sinia Decker who used Earp as her surname.  She probably did not know her surname since she was very young when her mother died.

Thanks

Beverley Caddel Ferrell