What no one has yet mentioned is she may have been told to leave the country. Her husband is meant to be some 'specialist', a spy or whatever. If he is valuable to the US the last thing they would want is for his missus to be locked up. Maybe the higher ups told her to fuck off. This is what happens in the real world which is why all this media bullshit is just that, it helps to fill some time on boring morning news slots and all day news slots, it also gives a little break in between the Brexit shite.
If she was told to leave she aint coming back. If she has D.I. she ant coming back and if it is neither then the only way she comes back is via extradition. Lets stop the circus and let the cops, MPs and diplomats get on with it.