It's not well known and I really hadn't ever planned to tell anyone but Xenia spilled the beans on her Live Journal so there's no point in continuing to hide it.  For the last 17 years we have told people we have three children, James, Kim, and Xenia.  This photo is of Xenia:

Yeah.  Identical quadruplets.  This will explain certain other things people have long wondered about.  Xenia maintains two Live Journals and her own website, gets nearly straight A's in school, has a boyfriend, and almost never gets in trouble (she always has at least a couple alibis).  In addition to it being rare to have identical quadruplets this set is even more rare in that they have identical fingerprints.  I figured this might come in handy someday but now that Xenia has spilled the beans that game is pretty much over.  Oh, well... Merry Christmas everyone.