Lost daughter of Benjamin Cooper

Looking for more information about Anna Cooper b. 1804 in Georgia to Benjamin and Temperance Cooper.She is not listed as one of their children in any documents I have seen, but she is their daughter.She married William Clark in Hall County GA in 1820, had 9 children in Georgia and then moved to Smith county TX in 1846.Several of her Cooper family are there in TX with her in the census, several on the same page.Including her eldest daughter, Tempy Ann, married to Lafayette J Sosbee. Her brother, Cornelius went to Rusk with his wife Rutha, which is a bordering county to Smith.Very curious why she is not listed as a child of Benjamin and Temperance. Any help????