I agree with everything that's been mentioned here. So much of these decisions are really on a per-parent/per-child basis. If you don't want to homeschool and you aren't interested in it, you probably shouldn't. If your child really wants a school experience, that's another thing to take into account. I would look at all your local options - traditional and non-traditional. Some of the GT families I know have the best luck at school are at some of those under the radar schools that don't tout the highest test scores. GT magnet schools can be great, or the might just be more busy work at 1 year ahead of grade level without much flexibility.
You're in a wonderful position to find out what you can and be asking around while your daughter is so young! I didn't even know anything about the world of GT until my son was almost done with kindergarten. Turns out we're all HG+, but DH and I were never IDed. So until our own kid started complaining wildly and having stomach aches daily, along with an alarmingly high test score did this all come together for us.
Good luck! I will say homeschooling can be wonderful if you can find a good local network of like homeschooling families.
