One of the neighboring packs sent Snow over when she was a pup to Willow because of overcrowding. Willow was glad to accept another wolf to her pack, but Snow was not overly keen to leave her pack and move to another one. She was quite stubborn and quiet for a while, but she eventually got the jist of things and started to have fun.
For a while she was one of the hunters, but when she got a little older, she started being a puppysitter.