I have a bit of info about your Francis Penelope Ketchum, but it seems that you might already have it. She was daughter of Richard who was son of Joseph who was son of Edward. Info about Richard follows:
Lived in Bledsoe Co., Tennessee. Van Buren Co., Tennessee in 1850 census. Madison Co., Arkansas in 1860 and 1870 census. Richard's gggrandaughter is Brenda Pett. email her at cpett@micron.net

Info about Joseph follows:
In the 1830 & 1840 census Joseph was in in Bledsoe Co., TN. There are two "unplaced" Ketchums - Edward Ketchum of Fannin Co., TX and C.M. Ketchum of Benton Co., AR and Montague Co., TX. These could possibly have been sons of Joseph or his brother David. These two are in addition to the known sons of Joseph. It's a possiblity that this Edward could have been Joseph's father.

Bledsoe County Court Minutes the widow of Joseph Cetcham was in court to settle Joseph's estate. This was on 3 May l847. On 5 April l847, Joseph himself was listed in the minutes, and it is obvious that he was still alive on that date. So, died sometime between 5 April and 3 May l847. His widow's name (second wife) was Martha, aka Patsy.