>>282267006
I think Martha's lack of relevance to anything is why the Martha arc exists. The content of that arc is the type of thing Axeman is most passionate about writing and I think he was just really enjoying himself with this character he could do whatever he wanted with without repercussions on the rest of the story.
He's going to brutalize Yor and to a lesser extent Anya with their backstories, but Anya's has to be light enough that she's in a relatively happy, stable condition just a year after everything ended. Everything is also very recent with her so the dangers that plagued her are still out there and actively threatening the family.
Yor has a bit more leeway since the worst of what she went through was probably close to 15 years ago so there's been time to "heal" from (read: bury) a lot of the damage. Plus, with it so long ago, most of what has hurt her probably isn't in play anymore. Of course, what is still in play is Garden and that's its own tangled web.