i think they are making abig deal about it because she is a woman who just had a baby. The other people on the shows kids are already pretty big and there fathers have been getting deployed there whole lives where as with Joan this is her first child who was just born and she has to leave and she might miss her first steps or her first word... im sure if any of the other main character soldiers had babies they would make a big deal..
of course i could be very wrong and she could die... i mean they havnt really killed off any main characters yet (well at least one that dies in war) and it does make for good, sad but still good, tv when people die
this is just my opinion of course i dont know for sure.