She's actually what's called a Tortoiseshell or Tortie for short. A true calico has large patches of black or grey, yellow or buff, and white. The tortie has black or grey and yellow or buff, but the colors are more mixed together. Sometimes they have white too. Here's a link that tells about them. They're both really pretty types of cats and always female. I think that's because the color gene is connected to the X chromosome and since a female has two X's, they can have more then one color expressed. A male only has one X and one Y so they can only express one color, the white seems to be controled by another gene.
http://en.wikipedia.org/wiki/T...
