It feels worthwhile pointing out something others may miss: you aren't using "sister" in the colloquial sense here at all. Simpson and Jobs shared BOTH parents.

It feels worthwhile pointing out something others may miss: you aren't using "sister" in the colloquial sense here at all. Simpson and Jobs shared BOTH parents. The couple were not yet married, or even really a stable couple, when Jobs was born in 1955. His birth mother gave him up, but then ended up marrying his birth father after all and subsequently having Simpson.