For rescue, I used to get to help doing the puppy tests. I LOVED doing that. The person who did the tests was a Delta pet therapy evaluator. She had the foster take the puppies to another volunteer's house where they had never been, and would not meet the puppies prior to doing the test. Which meant I also could not play with them until after the test-difficult!
Then their foster/any known persons would have to leave-we tried to have setups where they could watch without the puppies seeing/sensing them.
So there were the puppies, all alone in a place they'd never been with two total strangers. It was really interesting and I loved doing it, no matter how tired I was. She used the Volhard puppy test. It was amazing in some of the litters the variations, and in others the similarities. And the idea of genetic temperament.
One group...oh my...they had a hard time with the tests themselves.
And my poor Mariele, who I ended up adopting (who was neither a GSD or a baby puppy during her test-but was
), was the one we laughed as the first ever to actually fail the tests-she went catatonic for all of them, it was actually heartbreaking.
So your friend would want to find someone experienced in doing the tests in addition to her own careful observation of the puppy's behavior, as well as her ability to read and understand purchasers (not what they say they want necessarily, but what they should have), in order to make the best matches.