The hardest thing for me to do is to take one step at a time. But having DS5.5, I've had no other choice. When his teacher, who initiated the whole grade acceleration process, had her concerns about what to do when he's 15, and his classmates are 16 and driving, I simply stated "we'll cross that bridge when we get there". Maybe by then a private school will be more suited for his needs - maybe homeschool... I don't know, and I can't think about it now. What I do need to do is focus on where he's at now, and what his needs are now.
Plus, as someone who has first hand experience of the hoops you need to try to jump and lines you need to try to cross PRIOR to kindergarten, it's really not worth the stress (both for you and your DD) of trying to jump the hoops and cross the lines now. Of course, keep track of your DD's progress and things she is working on, etc... but cross the next bridge when you get there.
And do keep her involved in things to expand her social skills. A lot of times, gifted kids have a little difficulty with that part since they are more advanced academically than their peers.
Good luck!