Cats may have minds of their own, but they still learn from how we treat them. A sure way to create fussy eaters is to mix up or change their routines, or panic at the first sign of rejection by tempting them back to the bowl with tidbits from your table. They'll quickly learn how to manipulate you to feed them 'owner' food rather than a healthy balanced diet. Think about it from your cat's point of view: what would you do if you were 'rewarded' with a treat every time you didn't eat? To avoid fussy tendencies, your best bet is to pick a routine and stick to it.
If your cat isn’t normally picky about her food and you've avoided creating "problem eater" habits, a trip to your veterinarian may be in order. Any deviation from her normal habits may be a sign of illness.