I agree with Dude. Testing is expensive. If you plan on homeschooling anyway, then just move her along at her own very advanced pace. If you're looking for a program of some kind, then by all means test her.
FWIW, my DD5 in Kindergarten, IQ at the borderline-PG-range, is struggling with high 1st grade books, and flying through mid-2nd grade math. So by comparison, I'd say your daughter is more than just bright.
DD5 and PG DS7 both get grumpy when given extra work -- my son particularly hates writing, it's not a sign that your daughter isn't as smart as you think.
Also, her spelling is impressive!!!
