Meerna is one of the ironhand gnomes trapped with Nere. She will either die alongside Nere in the cave-in, or be thrown into the lava by Nere after freeing them.
Involvement
It is impossible to save Meerna. If the party frees Nere, there is no NPC of Meerna that exits the cave-in. Rather, she is solely part of the cutscene immediately following. If the party does not free Nere, she will die in the trapped room with him. Meerna's cruel death is apparently Nere's Kick the Dog moment, and thus indispensable to the story.