Disney do documentaries too & the David attenburgh series' (Africa, being the most recent,) can't be beaten. You may need to vet the attenburgh ones if dd is sensitive (in one episode of Africa, a baby elephant dies). But they are wonderful & my dd, also 3 loves them. Her big passion in also nature.
You can't assess gifted and talented until in a school-like environment, I expect your HV was just impressed by her and had no other term to express it.
But if you want to show her TV (you don't need to at this age, really) I would recommend either National Geographic for Kids or Discovery for Kids - both produce nature related documentary-ish kids shows.
We've been told dd is gifted and talented by the health visitor but I'm not sure if its too early to tell?
Anyway regardless, like any parent I'd like to encourage any interests she has and at the moment it's nature. She wants to know every single fact about everything to do with animals in particular. I've bought her some nature books which she loves but I thought it might be nice to watch some short documentaries together. Are there any programmes anyone can recommend or any sets of DVDs? She is 3. Thanks so much for any help.