So this came into to my mind and I have been thinking about it for a while, so these aren't NOT CANNON their just my headcannons if I ever do a crossover
Okay so Rob8n, Deena , and Josh:
Robin is Deenas older brother but never got the chance to see her grow up because of the damn grabber. Deena was born in 1978 which means Robin is 13 years older than her. Dead Robin wouldn't know who Josh is because he was born after 1978 the year he died but he still feels like he should protect him at all costs.
Finney, Gwen, and Samantha:
Cousins, Samantha is related to them by their dad, Samanthas mom and Terrance are related ofc(no wonder they act like eachother)
Vance, Cindy. And Ziggy:
Vance had older and a younger sibling that he loved but didn't show it Vance got kidnapped in 1977 leaking into 1978 and then got killed in 1978 which led to their mom drinking and dad leaving. And you already know what happened in the summer of 1978 Cindy and Vance are together ziggy is the last sibling alive
Kate, Amy, and Bruce:
Kate is the middle child she lives with her aunt because some things happened in her old school, Bruce and Amy talk to her twice a month, but then Bruce got kidnapped and killed. Amy stopped talking to her less, she called once more just to find out that Kate has been killed to, she hasn't talked to anybody since and if she di it was short responses like "yes" "good morning" "love you and "bye"
Griffen and Isaac:
Griffin is a descendant of Isaac(not the killer, sarah fiers friend"
Simon and Billy:
Are cousin related to eachother by their mom side
Comment if I should add anything, or if you don't like it.