Erin is around 5ft tall, with long wavy ginger hair and a freckled face and body. Her eyes are forest green, with a ring of gold around the pupil. She is quite slim, with very long legs. She has a slightly long neck which always makes her feel a bit self concious, and a sharp jawline. Her teeth are very wonky, and she is in the early stages of braces and can't wait to get them off. Her hands are very slight and delicate and her feet rather small. Erin has a little scar on her chin from when she fell of her bike 6 years ago, and one on her hand from when she trapped it in the door. Erin flushes easily as she is very pale, and she never tans.

Erin is extremely intelligent, but also quite modest. She is very patient and diplomatic and is very good with young children. She can be easily stressed and overwhelmed but at the same time is very dedicated and hardworking. Erin is very selfless but can sometimes be slightly self sacrificing. She is desperate to make friends and can overtalk and think easily, not making a very good first impression.

Erin grew up in the Scottish Highlands, not too far south from Hogwarts. Her family are part of the Lindsay clan however they had to move to Edinburgh for her dad's work. Erin has a younger sister and a dog and went to the local primary school. Her best friend lives across the road and they are sad not to be going to the same school. She had a very happy and loving childhood and lives near both her grandparents. Most of Erin's cousins are younger than her.

Erin was playing with her youngest cousin Ina by a pond when the cousin fell in. In her panic Erin reached out to try grab Ina however before she could the water in the pond and cushioned Ina, not letting her sink and pushed her towards Erin.