The children born before 1910 were not Jacksons but Chambers. Ceck 1900 census Belle Chambers living in house hold of Kellys. Also 1910 census all children are Chambers, she is divorced and Alva W Jackson is a boarder in her home. 1920 census she is a Jackson and a widow and all children have taken the surname of Jackson. She married Alva sometime after 1910. Also Alva W Jackson was adopted by cousins I think William Kirby and Mary Ann Proctor. I think if you check this out you will find it correct, there is even a tree listing Alva.