Sometimes they just stop eating. If her environment is the same and there is nothing new to stress her out, just keep introducing what she has eaten in the past every week (or every other week if you don't have another snake to give the food to). Winter is a common time for snakes to stop eating, and the picky ones will start eating again in the Spring.
As long as she isn't losing any weight you don't have anything to worry about.![]()