I can't remember the Martha-Clark scene in Phoenix very well--do they actually talk about the miscarriage, or does Martha just issue blanket forgiveness for everything (Clark running away, what Jonathan had to do to bring Clark back, etc.)?

Clark starts to bring it up to apologize -- I think he even gets as far as saying something about "the baby" -- and she cuts him off with something along the lines of "We never blamed you." I remember it because it was kind of a Thing in the fandom at the time because after the ep aired, there were quite a few ep reviews where people were basically all, "Um, Jonathan sure as hell did!"

A behind-the-scenes anecdote: Apparently, there was talk amongst the creative team of going for the darker version, where Martha did hold Clark accountable and Annette O'Toole was appalled at the suggestion; she didn't think that was at all true to the Clark-Martha dynamic. So Annette is kind of responsible for how it goes down in Phoenix. She was apparently quite adamant that Martha not be portrayed as blaming Clark in any way for the loss of the baby.