I'm pretty sure I didn't say a YA novel must only have one protagonist, because that would rule out my own WAYFARER among numerous other books that have multiple MC's! And I wouldn't have said you shouldn't name the other significant characters in the book, because (again) that would disqualify the query I wrote for KNIFE, which mentions Paul McCormick and Queen Amaryllis as significant players in Knife's quest.

What I do remember saying, or at least intending to say, is that the query should keep the focus on the main character and his/her dilemma. But if other people play significantly into the MC's story (or if there is more than one MC!) then of course it's important to mention them. My initial remark was in regard to the line about how Kiril's choice affects "his family" and I felt that way of putting it was too vague and drew attention from the main story. Telling us about Niki, though, since she's a crucial character who is instrumental in helping Kiril in his quest -- nothing wrong with that.

But yes, I quite understand the exhaustion. I'm feeling much the same way right now after some comments I got from a beta reader, and need a few days to mourn my own failure process them and figure out how to use them in revisions. Take the time you need! The query will be better for it.