Apologies, OP, I didn't mean to offend. I was simply wondering why you cared about that one snapshot in time, rather than taking the everyday picture she presents to you as more representative. Are you and/or OH likely gifted? If so, I might indeed want to test, but otherwise, I'd assume your eldest may just be an outlier, and keep an eye out for possible learning disabilities in your younger daughter, just in case.
Because it is, IMO, a bad test, because it is possible that the child is not being adequately challenged, and because private testing can yield useful information. I have always heard test one (sibling), (with the right test) test them all. Being underchallenged in elementary school is not without consequences.
