Why do you like playing Beth?
Kelly Reilly: I love playing her. She’s such a layered, complex character, and I think she’s written so perfectly. She’s one of the most intelligent characters I’ve ever played, and she’s unapologetic. I really enjoy playing someone who’s imperfect.
There’s no rulebook with her because she’s also not role model. She’s deeply wounded and deeply brilliant and deeply loyal.
She certainly holds her own in this male-dominated ranch world.
She doesn’t have to fight, she absolutely wins every single time. That’s one of the joys playing this character; it’s not the same [story] you hear other times about a woman trying to fight her way and prove herself in a man’s world. Beth is so true to herself.
Why does she have the biggest problem with her brother Jamie (Wes Bentley)?
She sees him as incredibly weak as a person. He’s very self rewarding and wanting to better himself for his own egotistical reasons rather than for the benefit of her father or for the ranch. I think their feud has been going on since they were very young. He blames her for their mother’s death where as nobody else does. Jamie has some bitterness to him.
I kinda think they’re like twins in a weird way. They’re so attached to one another; they can’t escape one another. They’re like the other side of the same coin. Me and Wes [Bentley] have a great time with these characters.
source of post https://www.tvinsider.com/704903/yellowstone-kelly-reilly-interview-beth-dutton/