1923 star Aminah Nieves definitely has some theories about how her character, Teonna Rainwater, fits into the family that fans were first introduced to in Yellowstone.

In the Kevin Costner-led series, Thomas Rainwater (played by Gil Birmingham) was a major player in the Montana community and among the tribal population. In 1923, the Rainwater story gets its start with Teonna, who escaped from a reservation school in season 1 and went on the run, finding her Dad, Runs His Horse (Michael Spears), and friend Pete Plenty Clouds (Cole Brings Plenty in season 1, Jeremy Guana in season 2) along the way.

Season 2 ended with Teonna’s race against the clock finally over, as Father Renaud (Sebastian Roché) and Marshal Kent (Jamie McShane), who had been hunting her for months, were both killed and she was cleared of all the murder charges leveled against her.

The open-ended conclusion to Teonna’s story was frustrating for Nieves, 27, as she tells PEOPLE “no one knows” what’s to come in her character’s story.

One thing she does “absolutely” believe, though, is that Teonnah is the ancestor of Yellowstone‘s Rainwaters.

“I mean, I would hope it is what we think it is, right? ” she says. “But I guess I’m not supposed to tell you yes or no.”

Pointing out the similarities, she calls Thomas and Teonna “the T’s,” as she says she “would” guess Thomas is a descendant of her character. “Now how far [away], we don’t know,” she adds.

Speaking to the finale episode overall, Nieves says that she “didn’t” expect Teonna’s story to end the way it did — nor did she expect a lot of the other season 2 developments for her costars.

“I didn’t expect a lot of the endings in season 2 to be the ending. I think we all had so many different speculations and we’re all kind of chatting with Taylor [Sheridan] and [director] Ben [Richardson] in season 1 about what would happen in season 2, and [it was] completely different than any of the chats we’ve ever had.”

Of Teonna’s freedom, she says, “I was not expecting that,” but she’s still holding out hope for more of her story.

“I would love some closure for T, and that’s why I’m hopeful. I’m hopeful that she has a full-bodied life. I’m hopeful that she has children and is able to continue and stand and fight a good fight.”