Was this a test that a child could be voluntarily signed up for by their parents? In my district in a different state, the students were first selected based on standardized testing to then take the IQ test like exam to get into the program.

Unrelated but I'd love to hear the story behind your user name.

I'm not so certain that a test like that is proof of anything other than that someone has the resources to study for that test. Seattle's system seems to have been a magnet program (where such tests are maybe appropriate) masquerading as a gifted program. One has to wonder how many gifted students went underserved so that such a magnet program could be maintained. Sunsetting it for a neighborhood program seems fairer and more effective.

In any case, it's good that you've observed your daughter's failure to achieve without an extrinsic impetus. It's probably a good time to sit down with her and determine what excites her intellectually so that she can be empowered to pursue that subject independently. I can tell you first-hand that relying on a school or school system - even one that routinely sends graduates (minority and white, working and middle class) to highly-selective colleges and universities - to shepherd students into stable and lucrative careers is currently a fool's gambit. Academic achievement is often necessary but not sufficient (and also more expensive and time-consuming than incorporating a measure of autodidacticism.)

The OP strongly tries to claim (before contradicting herself in the concluding pargraph) that gifted is a major psychological difference, not merely being smart and a fast learner.