The 1880 census of St. Clair Co AL shows Alice G. McDill b. abt. 1871 in the household of G.T. McDill. I think she was a daughter by his first wife, Adelia Ann Nichols, who died in 1874. I do not find Alice McDill in the 1900 census.
I think Alice McDill Cowan must have died before 1900, possibly soon after her daughter Viola Cowan was born in Dec 1893, as Viola was given to her cousin Leona "Loney" Downs Cook to raise.
In 1930 I think General Taylor McDill was in the IOOF Home in Ellis Co, TX, at the age of 81. There is a TX death record for a "Laylor McDill" 3 Mar 1931 in Ellis County. I haven't had a chance to go look at his death certificate yet.