I'm really excited to see what the writers are doing with mari and nat, because after Ben's death they've been paired up in a similar way to TaiVan, Shauna Melissa, or Travis and Akilah.
Aside from the brief moment during the celebration, they haven't had any scenes devoted to just the two of them, but there has been a *lot* of screen time on them as a pair. In more than half of Natalie's scenes, Mari is present in a purposeful way. Either she's directly interacting with her, she's standing directly next to her, or in some cases the camera cuts away from Nat just to show Mari nodding along to what she's saying. And there's the two moments where Nat trusts Mari with being responsible for Hannah and Kodi and the escape plan.
Plus, Mari is the only other person on "Team Rescue" who doesn't have split loyalty. Gen loves Melissa and Akilah still believes in some version of the wilderness.
This show doesn't shy away from queer relationships, so maybe some sort of romance is on the table, but right now Mari is being set up as a sort of Right Hand Man to Natalie going into season 4. And I think that'd be a great dynamic.