Would a COMPNOR Agent be out of place here? Specifically, an agent working for the Imperial Security Bureau? She'd have a dual role, investigating both the strength and resolve of the Alliance forces in the sector, as well as the strange, possibly treasonous Imperial Intelligence-classified goings-on beneath the surface...
:) I was thinking this could lead to some interesting interactions, in that she is basically both an ally and an enemy to both sides. She could be working with the Rebels to uncover the hinted-at sinister plot, all the while preparing to strike said Rebels when they're at their weakest, simultaneously appearing to follow the orders of the Governor, but following her own agenda the entire time.
At the start, she will have infiltrated the Governor's staff as a junior officer (would it be Army ranks or Navy?), and will be searching for an "in".