She wasn't "in" the United States until she cleared customs, or at least until the plane touched ground. Much like Cubans who have no claim to asylum until their feet actually touch US soil. Just being enroute either in the US territorial waters or US airspace doesn't count. And she was not "residing" in any state.
She has no claim to American citizenship.
But wasn't she in American Air-space? I wonder how they are going to deal with that?
If I am not mistaken until the wheels touched down, the aircraft would be consider the soverign territory of Mexico as it was a Mexican Airline.
Any international pilots on the thread know for sure?