Mephibosheth was five years old at Saul’s death. He may have been thirteen at David’s accession to the throne of Israel. In the eighth year of David’s reign over all Israel he would have been twenty-one. His having a son at this time indicates that we are about the 10th year of David’s reign.
Micha - Or Micah; who, as far as we know, was Mephibosheth’s only son, and had a numerous posterity (marginal references).