Definitely each keet has his or her own personality, so you learn to tell them apart. It's like if you had a batch of kittens in your house - they might all be "grey" but they would each have their own look in some way. Pinto has the white spots and Santo is all blue, so to me it's obvious when I look over which is which. But someone just visiting might say "Oh there are two blue birds".
Kacey - I'm sure once you show her how well you do with your current keet that your mom will let you get another to keep her company
It's not harder to take care of two keets, you still feed them and clean the cage at the same rate