As Mother and Jacob make their way back towards the caves, Jacob says that there is a storm coming. She tells him to go gets some firewood before it rains and tells him to be careful. Jacob says that he'll see her back at home and leaves, but clearly seems to Mother know they won't see each other again.
As Mother returns to the cave, she finds that it has ben ransacked, including the tapestry which is ruined. She discovers the Man In Black's Senet game on ground and removes a black and white stone from inside. As she examines the black stone, MIB plunges the dagger through her back and she falls to the ground.
MIB leans over her body and asks why she wouldn't let him leave and she says "Because I... I love you." She then says "Thank you" as she dies. He weeps over her body and then sees that Jacob has returned.
Jacob repeatedly asks MIB what he did and then leaps forward and attacks him, much like he did as a teenager. After pummeling him in the face he finally stops. We'll pick this up in the next post.
So Mother seems to have the same feeling about her death as Jacob did when Ben stabbed him. They both didn't fight their deaths and Mother even thanked MIB. Why is that? Is it just their time to move on after thousands of years of performing their job?