In my experience of tribunals, she would need to find representation. Usually advocates only take on cases which are likely to have a reasonable chance of word winning, because they're not cheap if you lose. Unless her house insurance covers it, or someone does it pro bono, she will need a good case. Which she might have so who knows.
My guess is that RB will pay what it takes to settle.
On the other matter of Sergio, I wonder if RB are complying or sucking up to the F1 or FIA as they are going to need support later down the lane. It's all power and politics. RB would definitely hold it over the FIA if they were asked to keep Sergio on for financial gain.