Your DD reminds me of DD's age-mate cousin. She talked extremely early so much so that I was convinced there was something wrong with DD. Right now, DD is the child who appears more advanced because she has academic skills but I believe it all comes down to developmental differences at this age and I won't be at all surprised if the two cousins are reading at a similar level by the time they are 13 although their interest might be quite different.
I also know a few HG+ children who looked average or below average in their reading skills until they were 6, 7, or 8 so unless you get that nagging feeling that there may be learning problems, I wouldn't make much of her reading readiness.
As for math, some children show early aptitude for math but I do wonder what that means. DD is a mathy child right now but in 13+ years, would it matter? I don't believe that all children even out by 3rd grade (bell curve doesn't flatten out when children reach their 9th birthday!) but without the drive or passion, having natural talent won't get her anywhere.
So, I am trying to focus more on helping her cultivate the ability to reach her own goals rather than thinking about her "gift."
I think in a big scheme of things, rural NZ is a wonderful setting for raising young children especially if you would have an access to high-speed internet and a good library. There may not be many choices of extracurricular activities but she'd be safe and free to explore the outdoors. But, to be perfectly honest, I wouldn't want to move away from Christchurch if I were in your shoes but that's probably the city girl in me talking.
