I don't have Frances Klepper married to Thomas Jones. But I will send this question onto someone who knows the Klepper Family far better then I. Most of my information which I try to document as I go along is from Lucille Clepper Mahrkam who published a book on the Kleppers several years ago. I also looked back for Isaacs in the Kleppers. I did see an Isaac born 1803, MD whose parentage are listed as Samuel "Clip" Klepper and Nancy ?. This Isaac seemed to move onto AL, IN, and TX.
Samuel and Nancy Kleppers children's birth dates seem a bit goofy - I suspect that there are missing children. Samuel paid taxes in 1811 in White Co., TN but seems to have been in MD, TN, IL, MO, AL, and TX. A lot of information could have been lost in all that movement.
I don't know if this will help or not but it could be a clue.
Pattie
Frederick Klepper > Jacob Y Klepper > Nathan Klepper > William R Klepper > Archie Lee Klepper [1894-1872]