Charles’s middle name should not be taken to indicate a relationship to any other Pettit with the same pair of given names. It would represent being named after either the fictional character Sir Charles Grandison or his namesake, the influential revivalist preacher Charles Grandison Finney (1792-1875).

See these articles:

http://en.wikipedia.org/wiki/Charles_Grandison_Finney

http://en.wikipedia.org/wiki/The_History_of_Sir_Charles_Grandison

Scott Co., Ky, death records list Elizabeth Pettit, age 38, married, died 12 Sep 1878, cause of death childbirth, birthplace Ky, parents James & Mahala Wright, father born in Virginia, mother born in Ky.

1870 census of Scott Co., Ky, Lytles Fork precinct, Little Eagle P.O., enumerated 18 June, lists on p. 20 as family #154:
Pettit, Charles, 33, post railer; Elizabeth, 27; John, 7; Margaret, 3; Henry, 2; Charley A., 5/12; Bernie, Lucinda, 12. All born in Ky.

1880 census of Scott Co., Ky, Lytles Fork district, enumerated 25 June, lists on p. 39 as family #328/329:
Petit, Charles, 41, farmer, b. Ky Tenn Va; John A., son, 17; Margrett, dau, 14; Henry E., 13, son; Charles A., 11, son; Francis A., 8, dau; Joseph A., 6, son. All children born Ky Ky Ky.

The next household is that of Charles’ brother Andrew.