0.) Please don't refer to a cichlid as 'pregnant'. They don't get pregnant.
1.) the eggs will not be fertilized unless you have something else in the tank that is male and is capable of of crossing with the jav (i.e. most central americans), in which case it may have fertilized the eggs. Fertilized eggs are brown/tannish. Unfertilized/damaged/diseased eggs are white. If they're mot fertilized, you can keep it there and the jag can eat her eggs to recoup some energy that she expended in the egg-making process.
2.) Depends on how much of a protective instinct she has, even if she sees most of her eggs going off she might still want to kill everything anyways.
3.) They may stop feeding, though it varies greatly based on the situation.