Here's a listing of my Civil War Garretts and their siblings. I am a g-g grandson of both Jackson and his brother Lewis. This might be of help to you...

1. Juliann Margaret Garrett, b. Feb. 19, 1833; d. Jan 03, 1916; m. George W. Dockery.
2. William Riley Garrett, b. Dec. 06, 1834; d. Dec. 06, 1926; m. Dec. 02, 1856 to Rebecca Jane Waters.
3. Martin VanBuren Garrett, b. Nov 14, 1836;d. June 26, 1899;m. Sept. 1857 to Louraina Dockery.
4. James Martin Garrett, b. 1839;m. Feb. 28, 1858 to Amanda Grizzle.
5. Henry Eli Garrett, b. 1840;m. July 29, 1860 to Harriet Dockery.
6. Jackson Garrett, b. 1842; m. April 01, 1860 to Hulda Woody.
7. Albert Garrett, b. 1844; m. Mary A. Seabolt.
8. Jasper Garrett, b. 1846; m. Lydia Collins.
9. Thomas Garrett, b. 1850; m. Dec. 24, 1868 to Lucinda Magness.
10. Lewis Dean Garrett, b. Aug 22, 1851; d. Dec. 26, 1941; m. Jane Matilda Radford.
11. John Garrett, b. 1852; m. 1869 to Charity Charolotte Postell.
12. George Garrett, b. 1856. m.Dovie Morrow
13. Willis Garrett, b. 1859. m. Evelyn Anderson
14. Sam Garrett?