Belle Starr was born 1848 as Myra Maybelle Shirley in Carthage, Missouri. She graduated from Missouri's Carthage Female Academy, a private institution that her father, John Shirley, may have helped to found in 1855. She received a classical education and learned piano. She knew Greek, Hebrew, and Latin. .
This episode has a major anachronism. Dr Quinn says Belle Star was 14. If Belle was 14, the year would be 1862; however, the show is set in the post Civil War(1861-1865) so Belle would be late teens to 20s.