Not knowing anything at all about your daughter have you considered that she has some possible LD or other issue that means that she is compensating for with her outstanding IQ? Compared to an ND child she could be making great progress, but with huge effort. It would certainly make for not enjoying school or being very motivated. But so would personality.
My DH and I were both "late bloomers". I was in remedial reading/math classes in yr3 and then top of my grade by yr5, twiddling my thumbs until the last year or two of school (by which point I had no idea how to study or time manage, never having needed to). My eldest DD, who has both of our strengths and both our weaknesses, and is G/LD also seems to be following a similar path. She was coming along great guns at 4yrs old, fell apart when she hit school and now in yr4 it's all really coming together for her again and I suspect another year from now she will be as far ahead as she was behind a year or two ago.
My point being, for some kids they may not really show the fruits of their giftedness early in their schooling. If your DD is gaining and gaining each year, even when behind, I would not be at all surprised to see her really take off even more when she hits "average" to "above average" for her peers, and then you may really hit some problems if you have moved her both out of a gifted school AND put her back.
Grinity often advises that the ideal fit for a gifted child is the class where they will get 90% with some effort. And that makes sense, they have to work, they can't just phone it in, but it's not so challenging that their self image is damaged by being unable to achieve well.
One more thought - just clarifying here. Your DD essentially started her first year of school in Yr2 (having resisted homeschooling for K)? And she was 6 yrs old? My own DD, mentioned above, has perhaps had a weirdly similar journey, for completely different reasons. She started a new school at the beginning of yr2. She is G/LD and it had not been picked up at the first school, so really her first two years of formal schooling she learned some good general knowledge but it might as well have been two years of play based learning with no formal instruction.
When she started Yr2 at the new school she was assessed by them as beginning of K reading/math level. By the end of Yr3, 2 years later, she was above average in one or two areas, below average in a couple, but over all "average". They don't like to tell us these things directly but at a guess she was sitting somewhere between the 30th and 50th percentile for her class.
She's now half way through yr4, instead of the gains slowing down now that she's caught up, she's gaining faster and faster. At the end of Yr2 we worried she should repeat. At the end of Yr3 we were glad we hadn't repeated. By the end of Yr4 I think she will be performing really well for her cohort and I would not be surprised if she is needing extension in Yr5.
Your child is not my child by any means, but they have both started "proper" education in yr2 very behind their peers, and been catching up steadily. My daughter is 6 months further along than yours and for us, the gains are only accelerating. Make of that what you will...
