Comments of chapter undefined of Reincarnated With The Strongest System

I've chosen violence today so I'm sharing a theory for a future arc. William makes it to the home of the elves, is moments away from seeing his mother for the first time in his new life, when the group opposing his mother step in and act on their plan to get rid of william and his mother, she dies before they get to reunite and the primordial goddess gets her Prince of darkness showcased with the return of the elves missing demi-god clad in darkness hovering behind William.

We know of William but we don’t know of others? Children implies more then one, right? Who are the other(s)?