Some females are even thriving and getting ready for egg sac number two.
Many have perished as a result of guarding the sac, though. Often the plant which the nest is on dies, and as a result there is less insect traffic, so the spider has no food supply.
Egg sac two seems to be the limit. My personal specimens appear to be on a self destruct course. They refuse prey and only care about guarding the sac.