@ Val — I hesitate to question the optimality of your daughter's choice of activities without solicitation & hope you'll forgive me if it's unwelcome, but have you and her thought about whether spelling bee preparation is the best use of her time?
Training for spelling bees may build discipline, constitutes cognitive exercise, and if done in the way that she's doing it, can improve one's understanding of language. But there are more conceptual activities that utilize higher order thinking skills to a greater extent. And very few people gifted people (or people more generally) pursue professions that utilize the subject matter learned to a nontrivial degree.
I tend to think that it's better to learn
(a) Ideas that have broad ramifications (such as some of those from psychology, philosophy, economics and evolutionary biology), or that fit into rich conceptual structures (such as those from math or physics)
and
(b) Skills that are useful in many real life contexts, such as writing, and programming.
There may be important considerations in favor of spelling bees that I'm missing, and I'd be interested in hearing any. I recognize that gifted children are often involved in spelling bees, and that there may be social benefits to being involved even if the activity isn't the most valuable in the abstract.
As a practicing researcher in one of the areas you mentioned in point a, I actually don't think a child should focus too much in them. I think social science is still relatively subjective and requires experience even a PG child would not necessarily have an easier time acquiring beyond their age. Time is better spent in mastering a more foundational subject. Math and etymology are both fine use of time.
