Re: Ambrose & Rebecca Lewis descendants
I'm sorry I've gotten your hopes up for nothing. There was nothing more in June's book except what I think you already know: "Shown in household of his grandmother Nancy Lewis in 1850."
I note that the last two children of their sister Nancy Jane, who md John Milton Harvey, were born in Cumberland Co., KY. Perhaps the boys moved near her? (I don't know my geography.) The last two were girls, Kittie Fanny and Rebecca Jane born in 1857 and 1859 respectively.
I don't have the date of Nancy Lewis' death (Mrs. Christopher Lewis, Nancy Lewis Powell's mother), but they must have made some kind of radical change after she was gone. I don't see any clue to where their half-brother Joseph H. and half-sister Elizabethlived, either, just in case they had been close.
My ancestor, William Powell, lived in Adair Co. also, and his children, who would have been William and George's cousins, were born about the same time. Could you find any connection with them?
Lucy Jane b 1828 md Henry Goodin.
Sarah Ann b 1831 md Jackson Holt
(she d. Dec 1857 in Russell Co., KY.
Mary Elizabeth b 1835 m. Zachariah F. Burton.
Oliver b 1836 m. Elizabeth McElroy; he d. in Guthrie, OK.
Nancy Belle Powell b 1839 (no further info)
William Henry b 1842, md Elvyra ?,Carroll Co. MO?
There are other children, but they were born 1844 and later, which I think meant they were probably never close to the twins.
If you find any possible connection to any of the above, June had quite a bit more on other descendants, which might lead to more clues.
And I've only given you the children of William. The children of Mary "Polly" who married Enos Rambo/Rambow/Rumbo were in Adair County also, but she had died before the twins were born, so not as likely that the cousins had been close. (Also, information about them is sketchy.)
Probably you've done a lot of looking along these lines, but I mention them as possible clues, anyway.