Would have to be limited/conditional immunity. You give her blanket immunity and she takes the fall for everything, insulating the Administration.
Presumably, that would entail her lying.
If she gets caught doing that, she goes to the can, blanket immunity or not. And likely for longer than if she'd just plead guilty with no immunity.
That's the beauty! She stays out of the can, but only at the cost of destroying those she believes in!