I think you're probably right about the "not much" but I'm not sure if the lack of success for Mozilla is not so much due to incompetence of the management as it is to the much stronger position of Google; some battles cannot be managed to win, only managed to decrease the loss.
Sure, but then what happens if she leaves due to small compensation (or for any other reason)?
To me it looks like "not much". She doesn't exactly have some stellar track record in the past few years.