Willow has ginger hair, typically left down, although sometimes curled or in a braid. They have pale skin, grey eyes, and an obsession with pink clothes. They wear contact lenses to see, as they don't like having to wear glasses. They're also rather short, barely over five feet.

Willow is usually quite nice, and likes to have as many friends as possible. They're also shy around new people, which has made it convenient for her to be homeschooled instead of going to muggle school. Once they meet a best friend though, they can be quite talkative and clingy.

Willow grew up in a house near the edge of a forest, it was a nice and cheery house, with not much around. Their parents, Violet Moss (33) and Lucas Moss (32) love her, and they have no siblings. When they started being homeschooled, they ended up playing outside more, and meeting another pure-blood named Sam. The two of them became best friends, and were almost always together until Willow went to Hogwarts.

On Willow's tenth birthday, they were playing outside and decided to jump rope. They picked up their jump rope and started jumping, not noticing when they accidentally let go of the handles and the rope kept turning. When they stopped jumping, they realized that the rope was still turning. They ran to tell their parents, who were extremely happy that they were a wizard.