I am curious if she is being honest or not(the monster),she might had been the one that said that she should live or similar,Assuming that her true goal is to eat the protagonist, My guess is that she fells happy that the girl don't actually wants to die,but actually waits for death. Is different(i had a time in my life like that,and kinda still do). She has no attachment to her life,but can't bring a end to it...but a soon as something can take her,at random a natural disaster. She accept it fine. I guess the only difference between me and her in that old that is that i would fight but not care if failed,but she has not even the will to fight. This will be a fun ride.