It's dollars to doughnuts the sister's claim to US citizenship is unassailable.
I suspect Obama's mother's true occupation is part of the background that creates some problems with his own records.
“...She [Senator Obama’s mother] may well have been working as an undercover covert agent for the CIA at the time as well...”
Where do you get this weird idea? The woman is described by high school friends as a “fellow traveler”, an aetheist who had strong feelings for socialism and who hated the United States. Hardly the type the CIA would want, especially since her family were New Deal enthusiasts.
You say that she was working for a US Government agency: was it the US State Dept., at an Embassy, or a consulate? They have lots of left wingers and neo-socialists working there.