This is the wrong family. The William Allison in question above was married to Martha "Patsy" Alexander. She died shortly after the birth of their youngest daughter Elizabeth Rebecca Allison in 1833 in South Carolina. He never remarried. The 1850 census for William Allison only shows 2 of his 8 children: William W. Allison, age 33 (listed as insane), and Elizabeth, age 18. They are living in Sugar Creek, Mecklenburg, NC dated Aug 17-19, 1850