Yuki started out as three years old, but is now over 500 years old because Haruhi started making time repeat itself over and over during the Endless Eight Episodes. :3 She's the only one in the SOS Brigade that could it was happening. Even Haruhi didn't know she was doing it. She basically repeated three weeks of summer vacation over 5000 times. And knew it. Pretty sucky for Yuki, huh?
This picture is based off of the time she was trying to figure out how to work a ratón and started circling it in the air. XD