Welcome, Twinkle Toes.
I want to second the advice to start reading up and looking at your schooling options soon. We knew GD5 was bright & advanced, but never thought about her being Gifted until she taught herself to read at age 3. Her Pre-K year at a private school was pretty bad since it was structured like a Kindergarten class (academically driven rather than play) and the other kids were just learning their colors, numbers and letters. She also was very talkative, active and sensitive and the teachers/school did not "get her" at all. She's now in public school Kindergarten and with no accommodations for her advanced knowledge, she is constantly waiting for the other kids to finish their work etc. and ends up talking, joking, getting up or other acting out and ends up in trouble.
Investigate all options first for a Pre-K that is either play-based or better yet a Montessori type with mixed age kids. Just visit schools and look for kids that match your DD's personality & intellect as close as possible and see how they react in the classroom & how the teachers interact with them. I so wish we had started early before school became the issue it is now.
If she is really already capable of doing first grade material, do not put her in a standard PS K class unless the school is willing to either accelerate her or give her work at her level. Depending on your school district, you may need to look for private schools that can meet her educational needs. Some here homeschool their kids successfully but you could think about that down the road when you see how she progresses.
Just my "2 cents".
