Originally Posted by Brutus
I agree with you that I'd love to see her appear, but if she doesn't, I wouldn't really consider it a loose end. Her role in the story, at least as we know it, basically played out. Skyler already found out they weren't paying Walt's treatment. At this point, given the way Walt left it with her in the restaurant, there'd be no reason (at least that we are aware of currently) for her to return.
By reappearance, I mean via flashback. Seeing her now, in the present time, would be a huge distraction, I agree.