Welcome, WorkingItOut! It sounds like you have a wonderful dd

Re sharing actual IQ #s with our kids - that's not something we plan on doing in our family. The # is only a #. I also feel strongly that it is our children's private information, and I wouldn't want them sharing it with others until they are old enough to understand how it might impact relationships or how others might react - because once they've told someone they can't take it back.
Your child is going to realize (if she hasn't already) that she is very smart or that other children don't learn as quickly as she does. There was a time in early elementary where our ds became easily frustrated when dealing with other people which as an adult, I could realize was due to their brains not working as quickly as his, but as a kid - he didn't have enough life experience yet to realize that was what was happening. So we did explain the bell curve to our EG ds and where his IQ in general falls on it relative to most of the people he will meet and talked a bit about how that might impact how other people learn or think compared to how he learns and thinks.
You also mentioned how extremely gifted intellect compares to LD in that it's a challenge to deal with. FWIW my ds also has a disability which causes him struggles with some academics in school (he's officially "LD" according to the school system). JMO, but the experience of gifted vs LD is similar in that both are outliers - the majority of our population is neither gifted or LD - but the experiences of living with each or parenting each - being gifted can be challenging, yes, but it is nothing like the challenge of being LD.
Re accuracy of IQ tests in young children - we've had two different experiences. Both my EG ds and my oldest dd were tested when they were 5. DS' scores have held up over time - and he's been tested several times over the years and with different types of tests. Our dd's scores, otoh, did not hold up and actually dropped by 20 points. I still wonder sometimes why there was such a large drop, but her overall academics and just knowing her - my gut feeling is the lower scores, for her, are closer to what's real. For me, the real clue is in knowing our kids well, and also watching how other adults react to them, particularly when they are small. We never paid much attention to milestones, but we knew our ds was very bright when he shared his ideas with us when he was very young. We knew our suspicions of how bright he really was when we watched other adults who didn't know him well talk to him

Hang in there!
polarbear
Hang in there! Yes, there will be times that it will be challenging raising your chi