I think that it depends on the individual teacher, and how strictly you draw the line on 'similar.' I remember that for years, we would visit my grandparents, and my grandmother would say: 'Oh, you're so lucky, there is a little girl also visiting that is just your age!'
It didn't take me long to figure out that from Grandmother's perspective, 'just my age' was anything within 7 years! Hardly my perspective at the time.
I do believe that everyone has an unconscious built-in 'IQ detector' How else do people gravitate towards 'similar IQ' spouses? I think that people's 'intrapersonal intelligence' varies, and that affects their ability to make conscious use of their unconscious ability.
The only way to know is to let her suggest a few kids for playdates and see how the pairing go. OTOH, there are other factors, besides IQ, that determine who enjoys playing with who. Above level testing would help, but since the tests don't perfectly reflect intelligence, and you are dealing with a small possible pool ( I would guess) I don't think it's that much of a problem that they aren't available.
You may bet farther by organizing a 'game night' with the whole pool and watching the kids as they play. I particularly like 'Apples to Apples.' The Jr. Edition might be better.
Best Wishes,
Grinity