Haven't followed her series of articles but if she travels she should look into the Utah concealed permit.
That permit would give her 31 states in which to legally carry.
In which case she would be in the market for her second handgun! (Although it is not immediately clear whether she would have a problem getting that weapon into a DC airport.)
I believe only Reagan National is technically within the district. After the district was laid out, Virginia took back all of it coming from within Virginia up to the western/southern bank of the Potomac. As I heard it when I lived in Arlington, Reagan National is built on fill extending out into the Potomac, and so is part of the District of Columbia. Dulles or BWI are usually better choices anyway.