Kaitlyn the cat is the mother of Katie the cat. You will find Kaitlyn or Katie in your town if you have visited a friend or have had someone come to your town.
If you have Kaitlyn in your town, you cannot make her follow you around. If you have Katie in your town, she will follow you around once you have talked to her. With Katie, you must have your friend open the gate. With Kaitlyn, you must have your friend come to your town. Just lead Katie to the gate and click on "I wanna go out!" once your friend has their gate opened. With Kaitlyn, open your gate and wait for your friend to come to your town.
Almost every Special Visitor will give you a gift after you help them. Even though both players helped reunite the two, only the person who found Katie in their town will get a letter with a gift included. Katie's gifts are:
Katie and Kaitlyn's Picture
Portrait (a drawing Katie made)
Lily Pad Table