I didn't find a marriage record for Edward Holmes in "White CO , TN ,Oldest Marriage Book 1809-1859" But I did find court records, none that gave Nancy's maiden name. Thought you might want them for reference.
This day the following persons were reported for not having given the list of their taxable property for the year 1836 and are subject to the payment of Double tax To Wit:
In Dist. 9 Nancy Holmes 30 acres land worth $200
This day Asa Certain Guardian to Alphonzo and Maniza Holmes minor heirs of Edward Holmes deceased his report upon oath which is Ordered to be recorded.
This day Nancy Holmes and William J. Bennett appeared in open Court and were appointed guardian to Alphonzo and Maniza Holmes infant heirs of Edward Holmes deceased and took the oath required by law and together with George Defrees and Anthony Dibrell entered into and acknowledged bond of three Thousand Dollars conditioned as the law requires.
Wills and inventories, Edward Holmes, pg 117 Will book B