1940 Nampa, Mary has bro/inlaw Wm HALL b c 1866 IN residing/visiting with her,,,,possibly same Wm in your cemetery d 1956, b KY
1930 census Chas b 1863 IN . Mary b 1866 Ger
1910 Fruitland Canyon ID HALL C F 50 IN IN KY; m 1x m 15y Mary 43 Germany [Pol]
1920 Fruitland Fayette ID HALL C F 52 IN US KY Mary 53 Germany; emi 1869, na 1881
I don't know where to look for a marriage.
Because of the huge differnce in his age, I haven't been able to find Chas on earlier census. There is an Abner/Patsy [nickname for Martha] 1880 Garrard Co KY, but they don't have sons Chas or Wm.I actually think Patsy should be Betsy, as his wife is Eliz. on 1870 census; b c 1845 IN; Abner b c 1813 KY Maybe a trip to your library for obits might provide Mary's name and/or Chas' siblings The only facts on a DC is the deathdate/location, everything else is up for grabs.