Hmm, slight discrepancy with the LN (and anime), there were 8 students killed by Ayaka there. Akari Misono seems to have survived this time. And indeed she appears to be alive and well, next to the cheerleader on Page 10. Wonder if that'll change anything that comes next.
Poor Erika and Nina, still don't even get an illustration. At least they got named unlike in the LN. Although, there are 2 random background girls in the middle of c13 (I've spent too much time on this) who I think would kind of have to be them, because we know what every other girl in the class looks like.
Though, while looking this up I came across a still of the anime version of that scene and Nina is actually in it with Runa and Asuha, but looks nothing like the 2 girls in the manga version. I think the version I watched didn't bother to sub the on-screen text there so I missed it at the time.