In Candide, why does the old woman cling to life even though she is miserable?

Afteris
flogged in Chapter 6, an old woman cares for him.  While with Candide in Chapter 11, she tells
him her miserable story of being captured along with her mother, her mother's killing, and her
desperate escape from death.  After reflecting upon her lost happiness and beauty, she remarks,
"I have wanted to kill myself a hundred times, but somehow I am still in love
with...