I just found out a couple of days ago about the whole Syd having a sister thing and I think its soo great because there have been so many fics about Syd having a sister and now it's finally happening on the show yay! We all know how exciting the Spy Fam Mission was with Syd Irina and Jack but wouldn't it be cool to have Syd, her sis, Irina, Jack, and Sloane all somehow be caught in the same mission or something?
Wait, if Syd's sister is Sloane's daughter, then it's really her half-sister isn't it? Unless she is Sloane's daughter and not Jacks?