Jasher has a few relatives mentioned in the series. One is his wife, Farfalee, a son named Lodan, and his brother-in-law, Drake. His brother Radolso was also mentioned twice in A World Without Heroes, it said his seed was destroyed by a displacer working for Maldor.
It is unknown how many deaths Jasher experienced before the series' beginning, but he dies twice in the series. In A World Without Heroes, he explodes when Kimp accidentally strikes the orb of orantium Jasher was carrying, and in Chasing the Prophecy, the Wanderer kills him. Both times, his seed remained undamaged and he was safely replanted.