Madelyn is a natural brunette, she had to change her hair color as a blonde for her role in Outer Banks. As a brunette she’s just as gorgeous and to be honest accentuates her eyes with her natural hair color. So I agree with what she said that some thinks she looks like Hailee Seinfeld(as a brunette)
JJ and Sarah siblings? Maybe. But maybe more JJ and Kie, as Luke said, in season 2, that Kie's mother was a Kook who loved hanging with bad boys, or something like that. Luke seemed to have very fund souvenirs of this... Continu to run our theories to the showrunner ❤️🤣