Hi Kay Good to hear from you again. Asa could have been married twice but like you, I can’t find any proof that he married a Nancy Todd.I believe that Nancy and Mary Ann Daughdrill are probably the one and the same although I keep looking for research that may show otherwise.I think that Nancy is a nickname for Mary Ann.Here is the census data I have on Mary Ann/Nancy followed by my reasoning why I think they are the same person:
1850 US Population, Choctaw Co., AL, p. 185 A & B, En. Date: Nov. 21 & 23, 1850. M432-3 "..Nancy..45..F..SC.." (b. ~ 1805)
1860 US Population, Beat 4, Meridian PO, Lauderdale Co., MS, p. 161, En. Date: Aug. 10, 1860. M653-583 "..Mary..56..F..Dom. Bus..SC.." (b. ~ 1804)
1870 US Population, Meridian, Beat 4, Lauderdale Co., MS, p. 21, Enumeration Date: Aug. 10, 1870 M593-735 "..Nancy..66..F..W..Keeping house..South Carolina..." ( b. ~1804)
1880 US Population, Beat 4, Tunnel Hill, Lauderdale Co., MS, ED 96, p. 48 & 49 (189D), T9-0653. En. Date: June 28 & 29, 1880 "..Whitlock, Nancy..W..F..75...mother-in-law (Of V.F. Hawkins)..W..At Home.. SC..SC..SC.." (b. ~1805)
The reason I think that Nancy and Mary are the same person is because Nancy is listed on the 1850, 1870 and 1880 census but stuck in between in 1860 is Mary.If the Nancy names were all together and then the Mary name (or visa versa) I would think they were different people but because they aren’t that way I do believe that they are probably the same person.Also the birth dates and place of birth fit them being the same person.Then in the 1880 census Nancy is listed as the mother-in-law of V. F. Hawkins (Celia’s Whitlock’s husband) so that would seem that they are the same.I guess she could have been a step-mother-in-law but with the other census information that doesn’t seem to make sense, at least it doesn’t seem to to me, but I am always open to new interpretations. The only other thing is that maybe Wm. Asa was married 3 times, first to a Nancy, then to a Mary and then to a Nancy again. I really don’t believe that is the case either as it doesn’t seem to fit with other findings.
But like you, I don’t think we will ever we'll ever find an absolute answer to the question, but isn’t it fun trying to figure it out.I guess that is what makes genealogy so interesting. Do keep in touch.