Cosmo is generally a curious, happy go lucky -if a little distractible- kid. She enjoys adventuring outdoors, and has spent a lot of her childhood alone, wandering along meandering creeks and across fields, but she is more than excited to go make friends, and learn a new way of life.

She has shoulder length wavy brown hair, an infectious, wide grin, and dark brown eyes. She often wears colourful T-shirts with cardigans over the top, and comfy pants that are good for exploring.

Cosmo lives on the outskirts of Chesham with her Mother, Annabel, and has done for her entire life. Annabel wont talk about Cosmo's father, and Cosmo can tell that it's a sensitive subject so she doesn't push. Instead she learns how to knit and garden and cook with Annabel, running free and learning the beauty of all things natural. Her first magic began showing itself early, but neither she nor her muggle Mother noticed until much later.

It was when she was 6, she had been watching a frog hop along the opposite bank of a river, desperately wishing she could hold it and suddenly she was! Things of this nature continued to happen until she was 9, which was when Annabel first picked up on her daughters unusual abilities. Cosmo had just made her first real friend and they were climbing an oak tree together when a branch snapped and Cosmo's friend began to plummet, screaming. Cosmo shrieked too, but both of their fears had been for nothing, because even after the 6 metre drop, no one was harmed. Annabel kept a much closer eye on Cosmo from then on, and was far less shocked when a letter from Hogwarts arrived than Cosmo was.