She's hurting changelings, not people. They're especially not people in the eye of the Rose Queen. [ And, based on Strange's slightly dismissive tone of voice, they're kind of not people in his eyes as well.

But as for Yuya's question, Strange continues to try and keep the calm tone going, mostly because he doesn't want to get into a fight in the middle of a public park. Muffling spells can only do so much if the party's visibly yelling. ]

She's the most powerful being in Portland and the only one who even has a chance of telling us how to remove the Severing. Besides, don't you want to know what's wrong with your memories and how to fix them to begin with?