In Friday the 13th if Pamela voorhees got killed how did Jason end up with a little sister?

In the "Friday the 13th" series, Pamela Voorhees is Jason's mother, and she is the primary antagonist in the first film. Jason does not have a biological sister; however, in later films, it is suggested that he has a connection to other characters, including those who are referred to as family or siblings in various contexts or storylines. The series often employs convoluted narratives and retcons, which can lead to inconsistencies regarding family relationships. Ultimately, the franchise focuses more on Jason as a singular, iconic killer rather than the specifics of his familial ties.