... she's a pretty cut and dry mildly gifted child in my opinion and just want her to qualify for the G&T program.
FWIW, this was what I told myself about my dd too--it was very helpful to have the WISC scores to get a clearer picture of her LOG and how to advocate for her.
Well, I did find a tester who suggested waiting til closer to the deadline for the G&T application for the most recent results. After speaking with the tester I really am curious as to her LOG now. My dd started out with such gusto and really floored me with her early development. For instance, without any instruction she knew all her letters and their sounds by 18 months. She had a bit of an obsession with letters, pointing them out and saying the sounds wherever we went which caused quite the stares in public. Later, while going back through videos I found clips of her at as young as 10 months pointing to letters and giving them sounds, albeit most were incorrect. At the time I had no clue as to what she was doing but watching the videos now I see what she was doing. She started to sound out words before 2 1/2, started spelling simple words around that time and would even spell them backwards for fun. Shortly before turning 3 she was writing simple sentences and was doing 100 piece puzzles (she had a bit of an obsession with puzzles from ages 2-3 1/2). But what I found the most astonishing about her at an early age was her drive, her drive to learn and achieve (i.e. requesting I teach her how to play chess at 3). I have never taken an approach to teach her anything (unless she asked) and really just took her lead with everything.
However, at around 3 1/2 she started to drop off her trajectory and lost her drive. As I don't believe in hot-housing I just followed her lead as usual and let her do as she pleased and as time passed she seemed less gifted and more along the lines of just a very bright child. While she was in pre-k (started a year early since she was advanced and ended up doing 2 years of pre-k) her teachers always had wonderful things to say about her and how she was the most advanced but I honestly didn't see anything too out of the ordinary.
Currently her biggest strength is reading (she's at a late 2nd grade/early 3rd grade level). We've just recently started some math workbooks to supplement the lack of math instruction at school. Today I gave her the Singapore Math Primary 1A placement test and she refused my help. She only missed 1 problem but it did take her awhile to finish it. I really don't think she's that math-y but I did admire her determination at figuring out the problems. Other than the reading she really doesn't seem all that gifted, more along the lines of bright and slightly advanced. So I've always felt guilty about her stagnating, blaming myself for not enriching her enough or encouraging her to do more, and left wondering what could have been.
I shared my dd's development with the tester today and she commented on something that I really didn't even think of. She mentioned how my dd's development seemed to drop around the time she entered pre-k and said that often times kids will dumb down to fit in with their peers. So now I really don't know what to think and even more interested to have her tested just to see what she truly is capable of.
Sorry for the long, rambling response. Thanks for listening if you made it to the end.

So, in the first place, I don't know if you've read discussion along these lines before, but it is likely that your perspective is skewed as to what typical development is. You are likely gifted yourself, probably members of your immediate family and extended family, etc. Often your friends and their kids are likely gifted (whether they recognize it or not) because those may be the people you are drawn to. So when the teachers said she was unusual, they were probably right.
Don't beat yourself up--you did you best you could with what you knew at the time and she is still a little kid! It is a gift to her that you are figuring this stuff out now--not like me trying to figure out in mid-life!
I had a similar parenting approach re: following the kid's lead and being anti-hothousing(which, honestly, I don't think is a bad one! it is just that the school environment can complicate it once they start), and if we hadn't moved to a place where the best pre-school happened to be a Montessori school, I think my dd would have followed a similar path. As I said, I only chose her pre-school because it had the best repuation locally, not because I was a huge believer in Montessori. It just happened to be a wonderful fit for my dd, and allowed her to learn at her own pace (mostly). (Of course after getting the WISC results I am kicking myself too for not doing more earlier, and my dd is already 11--so, I guess I should practice what I preach about letting go of the guilt.) But anyway, my point is that we just lucked into a good fit school for her, and it was when I was contemplating moving her out of Montessori for 4th grade (due to cost) that I found this forum.
Re: dumbing down to fit in--I saw that clearly with dd4 when she was 3 and started at the local church pre-k (3rd kid gets screwed--we were trying to save $) but I was only aware of what was going on from having spent time on this forum. We switched her to the Montessori school mid-year last year and she became herself again.
So, yes, the WISC results were well worth having (and would have also been worth it if her LOG had been in the MG range, too). And, really, your dd is still so young. It would have made a big difference in my life if I had known about all of this gifted stuff when I was 18, or 22--let alone 6. She is lucky to have you for her mom.
And this is slightly OT--but the book that really helped me a lot was Living with Intensity. You might check it out.