I don't think that anyone here is saying that a child couldn't possibly be known to be gifted as a preschooler. In your situation, I'd look at what seems to be a fit for your dd right now. As mycupoftea said, even kids who aren't gifted but are above average can achieve very highly and be accelerated. Playing Devil's Advocate, if you turned out to be totally off in your judgement of your dd, she's got to be at least bright, no? Especially if she would be one of the older kids without acceleration, I'd lean toward moving her ahead myself.
I think that the overall point I get from this type of discussion is twofold:
* IQ isn't set in stone and a person's relative ranking in relation to age peers may change over time. Some people are early out of the gate and others are slower starters, so it may be unwise to assume that early milestones or IQ numbers tell us a permanent ranking of a person in relation to others; and
* IQ tests are imperfect especially when dealing with people who aren't average. My dd10, whom I mentioned earlier with the MG-HG+ IQ scores a mere year apart, is a perfect example. Twice exceptionalities can mess with the total #, wild asynchronous development can as well (mine still had some really high -- 17-19 -- scores even on her lower testing), periods of jumps in development and periods of slow downs can also make #s fluctuate... Overall, the further you get from the mean, the harder it is to know that what you are getting is a fairly accurate picture.
