I just graduated with a B.S. in Biology (specializing in zoology/animal behavior), and I can let you know that marsupials as well as rodents are notorious (perhaps not the best phrase to use sorry!) for this behavior. A kangaroo will even throw a joey out of her pouch if she is being chased. As sad as it is, the mother is not being 'selfish' in saving herself, but rather by saving herself she is able to produce more young. Rodents will eat their young if nutrients are not available. This is instinct as they "know" (although it is genetic not really thought driven) that the babies would starve to death. Consuming the body not only serves to detere predators, but also gives the parents back valuable resources (fat and calcium) that they will need to rear another baby.
I am so very sorry for your loss, and I do not mean to sound insensitive with the straighforward biology. I'm merely letting you know that there is a lot of evolutionary reason as to why they do not only kill, but eat, their young. My friend also had her two gliders (who were also rescues) do the same with two separate litters, and it could be that they just aren't meant to be parents like hers, and perhaps nuetering is the best option.