Math is the thing that really gets me because she has had very early milestones for counting, counting backwards, skip counting, adding, and subtracting, but she honestly doesn't seem far ahead now of where she was at 3.
FWIW, I could almost have written that when my DS was, say, 4y10m. Then something flipped and he hasn't slowed down since. The only way I can account for it looking back is that his developing expertise with decoding the code that is print was much more interesting mathematically than anything else he had access to, at that time; it was only once he had that completely sussed that he was interested in other mathematical input.
FWIW I also remember frustrating unevenness at this kind of age and later. I think part of it is that it's difficult as an adult to comprehend where the difficulties are, and part of it is just that concepts don't necessarily come in a neat order. I have a piece of paper somewhere where DS wrote 49 as 409, *long* (I mean, at least 2 months :-) after I thought he had place value sussed. You have to learn to think "oh, that's interesting" :-)
I feel like I must be either under- or overestimating her math abilities, and providing her with the wrong sorts of materials, and she must be getting frustrated about it. I say that because she has regular interest that just sort of peters out without much progress. If she just seemed uninterested, I wouldn't worry about it.
Can we help with suggestions of things to offer? What kind of interest is she showing, and what have you made available already?
(I remember that this is the age we introduced DS's sum folder, with the rule that he chose what kind of sum he wanted and how many, we wrote that many of that kind of sum, he did them, we marked them, and then the sheet went into the folder. This system was only really active for a few months, but for those few months he loved it. ETA, ah, and in fact
here is the first post I ever made on this forum, including a list of mathematical things he liked then, just before turning 5, in case that's any use.)
To state the obvious, no IQ test is going to help you much in knowing what maths your DD is ready for!
