I struggled with that question, too. I think the answer is that no, not all PG kids have a "prodigious talent." But generally, they will have some area or areas that they show their advanced thinking skills.
It sounds like part of the problem might be linguistic. It is definitely possible to be talented at math, but it sounds like you think of that word as meaning artistic talent. I would just talk about some area where s/he learned to a greater depth with more ease than you might expect of his/her classmates, even if it doesn't seem "prodigious" to you.
