In the OVA episode of the anime, the viewers finally get to know how Misaki died (from leukemia)
But right before dying, she tried to reach out to a doll. In the same episode (And also in another episode where Mei was talking to Kouichi), Mei mentioned how dolls are hollow and how they "feed" on souls (I don't remember that line exactly but it was close enough to this)
Misaki DID mention that she could be saved. But she died.
My theory is that the dolls sucked out her soul (After all, it IS a horror anime). This is why she was reaching out to them. And this is why, maybe, Mei was shown to be remembering those dolls after news of Misaki's death reached her.
In fact, it is unusual how much the dolls are shown yet there role is almost nothing in the anime.
This is just a theory and I may have missed out some small detail that might contradict or prove my theory wrong. Please be free to comment your thoughts on the same and any other explanation as to why she could've been reaching out to the dolls seconds before her death