KeyMath is a good instrument, more in-depth than WJ or WIAT. But the untimed aspect of it means that fluency is not addressed. One of the interventions with the best track record for dyscalculia is Touch Math, which is a dot system. I'm surprised none of your special ed team know of it. (It's status is much like the OG of basic math and numeracy.)

If she really cannot attain automaticity after multiple evidence-based interventions have been implemented with fidelity, then she should have a calculator accommodation. I have a student who scored well on the KeyMath, but for whom I recommended calculator, due to the absurd amounts of effort she was putting into drawing massive dot arrays to do long division and multiplication.

...pronounced like the long vowel and first letter of the alphabet...