Jack is actually sort of self conscious about not being serious or old enough to be the Sorcerer Supreme, so while he doesn't super wear that on his sleeve, her judgement there does sort of hit home which he is probably a little awkward about.

He'd probably know her as both things, since I figure that Enclave people are more open with each other than they are with other people about some things, given the whole secret magi society thing. He probably secretly finds her a bit intimidating because she's sort of like Nivata but without the obnoxiousness.