Well, there's a fun theory floating around Reddit that I love.
Red = The Dissident
79 (from the Stewmaker's book and the same person in Berlin's pocketwatch) = Berlin's daughter, who fell in love with The Dissident
Lizzie = The Daughter of Red and 79, granddaughter of Berlin.
IOW: As has been suspected from the start, Red has TWO daughters. One is dead, the other is Lizzie.
I highly doubt that they are going to spend the entire show dangling the "who is Lizzie's father" thing out at this point. He may have told her to back off of it, but if we've learned anything about her character, we know she's going to start snooping. She clearly also knows he's her dad at this point. Or at least strongly suspects that he is, possibly leading us on throughout the season until an ultimate showdown discovery of who her father really is.
Meanwhile, I notice that the evil surrounding Fitch has certainly backed off an extraordinary amount. I don't think we're going to deal much with him until the last season of the show.
Honestly, at this point, cash cow, though it may be, I don't think they can go more than 3 seasons with this story. I always wondered how they were going to make it past one. I see three seasons worth of arc, now. Season 2 = Berlin/Liz's father, Season 3 = Fitch.