Did Senku's father have children with Lillian in Dr. Stone?
Heavy manga spoilers ahead read at your own risk:


  In manga ch 45, Kohaku asks if they are related to which Senku answers
that he and Byakuya are NOT blood related BUT they (he and the villagers)
are hundreds of generations apart so it doesn't matter.
Yes they had children, no they are not related to Senku.
(Note that they don't specifically show that Byakuya and Lillian were together but
there was the already married couple and they showed Connie and Shamil getting married so most
probably Byakuya ended up with Lillian)