I just finished a second play through today (my Doug file) and something struck me about Christa that I didn't catch before. As the episode went on, I only became more convinced. Note that I admit that this isn't exactly my theory, I searched around and other people are suggesting this too, but I just thought I'd make a place for us all to talk about it, and I apologize if there already is one.
Christa is totally in the early stages of pregnancy, and I'm willing to bet that it'll be revealed in the next episode.
There are three main reasons I believe this, but aside from those there are also certain other nuances that I think support this theory: namely, Christa is frequently very concerned with Clementine's safety and intrudes casually into Lee's parenting abilities, and these behaviors are compatible with eager, soon-to-be parents.
Okay POINT 1: The conversation we first hear between Christa and Omid as we're climbing the ladder. As Christa argues that joining the group is a bad idea, Omid begins to ask, before being hastily told to shut up, this curious question:
"But what will we do when...?"
Keep in mind, Christa and Omid are alone at this point. What imminent thing could he be referring to that could possibly require the help of strangers? One possibility is that Christa is newly pregnant, but isn't willing to share this information just yet.
POINT 2: Omid is perplexingly VERY excited to see that Clementine, a child, is part of the group. One way to explain his outburst is that maybe he is enthusiastic about becoming a father himself.
POINT 3: Omid becomes disproportionately upset when Lee saves him first instead of Christa. Again, he seems to trail off before he can finish his sentence:
"She's a woman! Don't you know that..."
His angered response could suggest that there's more at stake than just Christa alone... perhaps his unborn child was also in danger?
Anyway these are just some thoughts and I'm looking forward to seeing if I'm right. Of course, I could be totally wrong. Not bettin' on it, though
Let me know what you think!