I did have to do a bit of googling afterwards to get the proper view of the characters family tree's to see why they wouldn't exist I'll admit but i didn't mind that
I read a really interesting theory about the ending actually, not sure if you've read this one but it's basically that Martha and Jonas didn't have free will at the end and neither did Claudia, that this was what they were always supposed to do. The idea is that when Tannhaus makes his machine with the objective of preventing his son and families deaths that his machine found the solution and it worked, that it's solution was exactly what happened leading back to his family being saved by people that the machine as such created
Spoiler:
That's an interesting theory, I like it although the thought of Martha and Jonas having no choice makes it more depressing. I like the concept but I think it makes me happier thinking that the resolution came because Martha and Jonas chose to make it happen.
I'm conflicted yet again
The theory reminds me a lot of an episode of Black Mirror about dating apps, actually.