You know, in light of that, I'd say I was a little harsh in my above evaluation. The books did cover much intrigue between her tribe and the Romans, and between her tribe and others in pre-Britannica, both the ones more passive, more quarrelsome, plus one or two leaders who absolutely wanted to unite the island's peoples' together to kick the Romans' arses.

It also covered the relationship between Boadicca / Boudicca (etc) and her father, plus her and her future & later husband. It also addressed the generally low amount of respect that both the tribes and the Romans accorded to women being involved in discussions of significance. Of course, what set her apart is that she was also a priestess of the local Celts, just a slight cut below their druids.

So yeah, given how evidently little info there was about her, I'd say the books' creators actually did a good job with coming up with plausible material, even if reading-wise they're still kind of dry-ish. It's also pretty clear that the first two books nicely set up the premise of her being a more and more important figure in Celtic resistance, very likely to be seen in tomes 3-4, not yet published.

Let me know if you're looking for any particular angle of inspiration, and it might actually be there. I could kill two birds with one stone perhaps, and make a post about such at EGN.