Hmmm this is what I have on my William Pannell and Elizabeth Ballard
William b. abt 1820 either Tn or Ky (diff census say both) possible son of Benjamin Pannell and Elizabeth Herndon ( not proven) Elizabeth Ballard b. abt 1820 Georgia daughter of James Ballard and unknown wife ( not sure which wife his her mother) William and Elizabeth were married 26 May 1840 BlountAlabama(note same date as yours )
There children according to census records were James Reilly b. abt 1841 Ms Daniel M b. abt 1844 Ms Martha Ann b. 30 Jan 1845 Ms Jeremiah J. b. 20 Nov 1846 Ms Ursley Matilda b. 27 Jan 1850 Alabama George Porter b. 1852 Alabama Lucretia b. abt 1854 Alabama Nancy b. abt 1856 Alabama Levi Garrison b. abt 1858 Alabama Mary b. abt 1859 Alabama
William and Elizabeth along with their children can be found on the 1850 Marion Co Alabama census living next to James Ballard , Elizabeth's father . The reason I know that Elizabeth is a Ballard by birth is on 1850 and 1860 she is living either directly next door or a house away from her father on 1850 and brothers , and her brothers on 1860 , this William Pannell also bought land with James Ballard. Also James Ballard had sons named Levi Garrison Daniel Millinton Jeremiah J daughters Elizabeth ( that married William Pannell Ursula and Lucretia now look again at the names of William and Elizabeth's children .
How positive are you that your Elizabeth is a Ballard?