I'm not really sure what qualifies as a "first word." I tend to think it's the first time she says a discernible word that is actually connected to the concept it represents . . . like saying "ball" when pointing at an actual ball.
If, however, a first word is simply the utterance of a discernible string of sounds that we recognize in English as a "word," then Ali's first word (not surprisingly, given how much she adores the guy), is Da-da!