The problem, however, is that the Jedi don't know that because the Exile is of the same condition as Nihilus, she is the only one who could confront and have any chance of killing him in a straight-up fight.
Why is the Exile the only one who can kill Nihilius in a straight up fight?
The Jedi Masters cut the Exile off from the force because they fear that she might fall to the Dark side and become like Nihilius. But why would the Exile fall to the Dark side? She worked tirelessly and moved from planet to planet to save the Jedi Masters. If she would have been Dark sided, wouldn't she have killed the Jedi Masters?