Individual Details

Married Charles Smith of SC and moved to Pike Co, MS. Said to have lived on McGee's Creek. [I did not find a Charles Smith in Pike Co in 1820, when Nellie's brothers appeared to be there.] Nellie's name is also seen as Amelia and as Rachel or Rachel Nellie.

I believe some of the confusion concerning the lady's name comes from the following.
There was a Rachel Higginbotham who apparently married a Charles Smith:
William Smith of Georgia married 23 Aug 1814 to Elizabeth Greenwell of Kentucky, the widow of Thabite Fowler. They had a son Charles Levi Smith, born 8 Feb 1816. William's parents said to be Charles Smith and Rachel Higginbotham of Virginia.
There are at least two problems with the above. A daughter of Caleb's might have been born in Virginia but probably spent most of her childhood in Georgia and would have married in Georgia. The time frame for the birth of a child of Caleb's who would then be old enough to have a son marrying in 1814 is extremely short and likely impossible.

The following also sheds considerably doubt on whether or not Nellie was a daughter of Caleb:
History of Pike County, Mississippi by Conerly, p.81
Charles Smith and his wife, Nelly Hickenbottom, came from South Carolina in 1811 and settled on Magees Creek, west side, below China Grove near Peter Sandifer. Their children were Elias, who married Mary Gartman, Zachariah, Pharo, Joseph and Charles.
Nelly, as a daughter of Caleb, would not have been in South Carolina. The names of the children are exceedingly unlikely in the Higginbotham family of Caleb, and in fact the name Nellie [likely from Eleanor] or Amelia is not used in the family of Caleb. There are Hickenbottom families that are not the same as the Higginbothams from Amherst who were generally well educated and kept that spelling of their surname - although some of the families early on back in Virginia did use the given name Rachel. Granted Higginbotham is pronouned as "Higginbottom" - but in my mind that would make the stubborn preservation of the spelling significant.

The Higginbotham book by LaBiche, adds a son Thomas N. Smith, born 1804 in Georgia. Says that Elias V. Smith was born 14 Feb 1809 in Alabama, died 27 Jan 1899 in Walthall Co MS. His wife was Mary S. Gartmann, b. 6 Aug 1822, died 25 Jul 1899. Charles Jr. married Celia Lewis.

Father	CALEB Higginbotham (1752 - 1823)
Mother	MARYANN Cash (1755 - 1794)
Sibling	Robert H. Higginbotham (1777 - 1831)
Sibling	Nelson Higginbotham (1780 - 1860)
Sibling	WILLIAM HIGGINBOTHAM (1788 - 1852)
Sibling	Samuel Higginbotham ( - 1829)
Sibling	Mary Higginbotham (1793 - )
Sibling	Betsey Higginbotham ( - )