Alison Nightshade is the third child in a family of six girls. She's a tall girl and has ashen blond hair. Her blue eyes are piercing and give her an air determined and sure of her. Her harmonious face can make her think that she is a sweet person, but inside, she is very stubborn and obstinate.

She was born on May 20, 2008, a rainy morning. Throughout her childhood, while growing up, she saw her three little sisters being born as a result. She is very attached to the youngest of the family, Arya, even if she is only three years old. Her mother is Muggle and his father, a broom seller, is often away, which meant that she had to fend for herself most of the time, despite the presence of her two older sisters. When Arya was born, as her mother was already caring for her other sisters, she was the one who had to take care of her, and she developed a strong bond with her.

She studied at a muggle school until she was ten, even though her magic had already appeared. She was seven years old, it was in the middle of a school day. As the teacher read a lesson, she was angry with herself because she could not concentrate. It was then that the pages of her notebook started to turn on their own. When she got home, she sent an owl to her father who confirmed that his magic had been well declared.

Alison loves to read and animals. Despite her muggle mother, she knows a lot of things from the magical world thanks to her father, and she has read an incalculable number of books on fantastic beasts. This subject fascinates her more than anything.

She is very protective towards those around her, sometimes too much. She thinks she should always take care of everyone, and think of others before thinking about herself. Finally, her temperament is of a happy nature but also often worried.