This is to follow up my last post of 12-16-2009 at 10:24 p.m.
I went back and looked again at the 1910 census of Dewitt and Mary Morgan, and there is a notation on the census that Mary had been married twice.
Also, James, age 6, is listed as the stepson of Dewitt Morgan.
Therefore, I believe that your grandmother was Mary Jones who married Dewitt Morgan on 12-23-1905, that Jones was the name of her first husband, and that her maiden name was McEwen.
The marriage record of Martin Jones and Mary McEwen most assuredly belongs to your grandmother, and James, age 6, is most assuredly the son of Martin Jones.
The first time I looked at the 1910 census I didn't take the time to look at the original, and I should have.
Best regards--
Monterey