Jane's first... well, not word, because it isn't a word, but first wordlike entity, deployed clearly with reference to a specific and appropriate thing, would appear to be "nom".
"Nom nom nom!" she says of her food, or possibly "num num num," but obviously "nom nom nom" is more entertaining, so that's what we'll call it. We didn't really recognize how standardized and lexicalized away from generalized noises of food appreciation this performance of hers had become, until people we were sitting near at lunch today laughed and exclaimed over it. NOM NOM NOM!
And you'll be happy to know that we did eventually let her wear a party hat. Another way to look at this is that she allowed us to put a hat on her. Either way, there was a baby in a hat. Also there was a cupcake.
Option one: normal birthday snapshots.
Option two: Super art-directed film still Barry Sonnenfeld style.
Friends have pointed out that part of what makes the latter one look so perfectly full of artifice (and I confess that I love it as a photograph probably more than I should) is the perfect echo between the angle of the hat and the angle of the cupcake. What do you suppose is the plot of the movie in which this shot would appear, though? I can't decide.