Her name is Sasha and she is one of your fireteam members

During a mission you and Sasha where the last fireteam members because the others where killed by the hive

You and Sasha where in a dark cave where you started a fire and Sasha was was sitting on the floor afraid that she will die like the other fireteam members

then you hear her speaking quietly

“What if we don’t survive here? We will be dead…”