Sandford/Samuel/James/Hannah Allen are children of Charles Allen Jr, b. 8 Mar 1758 in Culpeper Co, Virginia, d. 28 Jan 1848 in Williamson Co, Tenn. Where did you get that name James -- please let me know. Charles Allen Jr was in the Revolutionary War as a member of his father Charles Allen's company. He is buried south of Franklin, Tenn. in the Allen Graveyard on Coleman Road. There IS a federal marker for his revolutionary war service in the graveyard (although county burial books indicate that no marker was seen when some ladies visited the overgrown cemetery in the 1970s).
Sandford G. Allen was born 21 Apr 1799 in Warren Co, NC and died 8 Mar 1865 in Williamson Co, Tenn. He married his cousin Nancy Allen in Warren Co, NC. Sandford is buried in the above-mentioned Allen Cemetery. Again, his marker is not noted in the Williamson County burial books.
Hannah Allen (her will reads "Haner") was referred to by the name "J.M. Brantley" in her father's will. Hannah Allen married John Brantley in Williamson Co, Tennessee on 6 April 1837.
Hannah's given name was apparently "Johanna" and in 1850 she lived with her sister Mary in Franklin. They are listed as "Joanna Brantley" and "Mary A. Swanson" along with Mary's grandson Edward Mayberry age 6. Edward was son of Henry G.W. Mayberry and his first wife, Adelia Swanson, who was Mary's daughter and who died at age 16. Henry G.W. Mayberry subsequently married Sophronia Hunter and then the widow of HGW's brother Americus Mayberry, Elizabeth (Dodson) Mayberry.Hannah's will on file in Williamson County, Tennessee mentions "the balance of my estate be equally divied betwen my sister Polley A. Swanson, Sandford G. Allen, Samuel P. Allen 7 Elbert J. Allen" and is signed "Haner M. Brantley, her mark". The name of her sister Polly (Mary) is not mentioned in their father Charles Allen Jr's will. Polly was the 2nd wife of an early settler of Williamson County, Edward Swanson and they married 21 July 1823 in Williamson County. They had a daughter Adelia who, as mentioned earlier, was the first wife of Henry George Washington Mayberry.Hannah does not state that Sandford G. Allen and Samuel P. Allen are her brothers (but they are), nor does she state that Elbert J. Allen is her nephew (son of Hannah's brother James).
Mary A. "Polly" Allen apparently was the older sister of Hannah, born about 1791 (census data conflicts). In the 1870 census she is living with her brother Samuel P. Allen (who never married).
The will of their father Charles Allen Jr only mentions wife Patsey Allen, sons S.G. Allen, Samuel P. Allen and daughter J.M. Brantley. Hannah Brantley's will explicitly notes that Mary A. Swanson is a sister. Charles Allen Jr's son James is also not mentioned in the father's will (Charles Jr died in 1848 and his son James died in 1840).I'm very curious how you learned of James's name and other information.