Ferne, you have jumped right into a Noblett-Nuckolls marriage date mystery. First, the Abraham Nebblett/Elizabeth Nuckolls marriage listed in Grayson Co. Marriages which you have here is Abraham Noblett/Elizabeth Nuckolls marriage. Incidently the Dave Nebbett and Sarah Denny listed is Abraham's brother. I descend through another one of Abraham's brothers, Isaac. As to the date of 1825, that has caused much debate among Noblett researchers. Explanations range from transcriber error to a second marriage for Abraham and Elizabeth due to religious reasons. One researcher's mother has seen the handwritten marriage listing and says it is 1825. What has been so puzzling is that most of the children of Abraham and Elizabeth were born before 1825, some think it should be 1805. We may never know. I am curious as to your reference of "abt 1790". Could you explain further and give source.
I have always had Elizabeth's father as Ezra Nuckolls.But there was a younger Ezra Nuckolls also which probably is the one listed in marriage record you posted. A Charles Nuckolls family is also related to Elizabeth and Ezra.
Hope you have good luck unraveling this family line. I have some info on the above Abraham Noblett, and a little info on Elizabeth Nuckolls. Let me know what info you might need on them and I'll try to help.Anything you might have on this couple would be appreciated.There are several researchers at the Noblett forum and Noblitt form. Try both forums and you might learn more about Elizabeth also.