I think others said in previous chapters, and she notes here, she was trying to live more as a mortal, thus limiting her expanded knowledge of the universe. She's been around so long, few things mean anything to her, but the joy in the surprise of her children and now husband make her want to keep on living.She can see the future, then why was she poisoned? I'm going to assume she let it happen so Reischel would heal her and become her husband.