Quanell X today said that Mona Nelson, accused of the kidnapping-murder of 12-year-old Jonathan Foster, admitted that she had dumped the boy's burned body in a northeast Houston ditch. But, the Houston activist added, the woman had no motive for killing the child. Quanell X said he attended Nelson's first court appearance today at the request of her family. Nelson, 44, this morning was advised of her rights by 182nd state District Court Judge Jeannine Barr, then remanded to county jail, where she is being held without bail on a capital murder charge