I think your Mary E. (Elizabeth) is a sister to my GG Grandpa, Christopher (C. L.) Johnson, found in Dunklin Co., MO. A Child, Mary F. Ledbetter shows up in census records as his niece. I've been working on this line for a couple years and I think I found Mary "Elizabeth" (from Tn) in her father's household in 1850 Madison County, TN...P. M. Johnson, father, mother, Eleanor nee: Thompson. Is this the right line?