Sierra is home!
She caught a "kitty cold" from one of the other kittens at the shelter, so they felt that it would be better to spay her after it's over. So she's home a day early. They gave me some anti-biotics drops. As they released her without spaying, I had to pay a $75 deposit. I'll get it back when the spaying is done. She should be ready in about two weeks.
She's exploring around the apartment now. She likes her new cat tree.