You'd think we'd be able to tell when/if she said her first word.
Well, as it turns out, not really.
Today she unambiguously signed "Water". Her "Nyeh!" has morphed into an equally unambiguous "Nuh!"--a short step from the phonologically correct "No!" And what we had hitherto taken for excited hand waving when the car stopped and it was time to get out--that turns out to have been the sign for "All done!" all along.
Combine that with the somewhat more ambiguous-but-still-compelling "dook!" [dog], "baba" [bubble and balloon], "bah!"/"wah!" [water, bottle, drink], and possible variations on "mama" or "dada" (possibly just the products of our fevered imaginations) and it becomes impossible to say with certainty what her first word is/was.