There's someone who looks like Sanae Tsukimoto who is beside
Tanabe-sensei who is crying.
But this can't be Sanae who appears earlier:
I heard Sanae has an older sibling who teaches in the school. (Or maybe it was actually mentioned in the anime.) So I guess it's Sanae's older sibling. I looked up fandom and it says Sanae's older sibling's anime debut in S03E02...
From S03E02 where Nishikata and Takagi are on library duty:
Is this Sanae's older sibling?