I'm no expert, but I'll chime in to back gratified on the notion of speed NOT being a necessary requirement for being HG+. I always say that I think there are (at least) two forms of GTness: fast and deep. Fast thinkers get hard things immediately (or almost) and thrive on timed tests. Deep thinkers don't get things quickly necessarily, but they tend to be "big picture" kids who put pieces together in surprisingly complex or creative ways.
Don't overextend the theory, of course. I mean, deep kids can do some things fast and fast kids can think creatively. It's more about the kid's usual M.O.
The other thing I'll bring up as a distant possibility--and please don't let this worry you!--is that I believe this sort of score discrepancy can be indicative of some learning disability. But as perfectionism can look much the same--and you already KNOW she's a perfectionist!--I really don't want to scare you. I just know that if I were in your shoes, I'd be asking about it just to make absolutely sure it's not an issue that needs attention. On stuff like that, I figure better safe than sorry, you know?
I'm betting it's perfectionism. I think you're right. My son is deep-not-fast, and we've had many of the same issues with completing work in a timely fashion. His scores on timed tests are always lower. Precision isn't rewarded in some of those tests.
