Ray, the only information I have about Alfreds in Tennessee is a couple of entries in the 1840 Sullivan County TN census. There was a Mary Alfred listed as head of a household containing 2 women aged 20 to 29, a boy under 5, a girl aged 5 to 9, and a girl aged 10 to 14. Three lines down is the household of Barney Bowman. In the household is a woman aged 20 to 29 who is, I believe, Elizabeth Alfred. Barney and Elizabeth moved to Russell County, VA, before 1850. I have a good bit of information on Elizabeth and her descendants, but no information at all about her parentage. She was born about 1813 in Tennessee.
I'm sorry--this probably doesn't help you at all, but I wouldn't be surprised to find that there is a connection with Isaac. Some of the information on Elizabeth and her descendants might be interpreted to mean that she was either Indian or Melungeon. Do you have any more information about Isaac and his descendants?