KATE/JAMES
Maybe it isn't worth it. Maybe it is. We can't really decide, and I know she's still processing everything and trying to work out a balance.
But maybe there's some good in there? In our world, the Avengers did stop Ultron. I know that doesn't change what happened in her world or in yours, but there could be some consolation for her knowing there's a world she helped save from him before it got to that point. And she got to see Yelena back home, instead of losing her before they could be together again. She's the reason the Blip happened - the Avengers undid the single most devastating moment in our world's history. We all know if it wasn't for Nat's sacrifice, that wouldn't have happened, and so many people would still be dust.
I'm not saying it's perfect, especially because we lost her again. But hopefully it means something.