Okay. Thanks to the movie, we now know for a fact that Wash's full name is Hoban Washburne. So what's Zoe's name? Variations I've seen:
Zoe Warren (IMDB)
Zoe Washburn (by extension from the movie)
Zoe Alleyne (sp?) (from the Visual Companion)
Given the fact that "Alleyne" is mentioned in one of Whedon's "mee-moes" as Zoe's name in the war, I think we can take it as canon that that's her maiden name, at least. So she's either Washburne or Alleyne. Not sure where "Warren" came from.