Ottilie is of shorter stature, about four feet and seven inches. She has dark brown hair that falls in messy waves that become slightly frizzy throughout the day. She has brown eyes that are dark in some lighting, but a brilliant amber when the light hits just right. She has dimples when she smiles, and a few freckles dotting her nose and cheeks.

Ottilie Canvendish is a very bubbly girl, though she's actually quite introverted until she becomes comfortable with the people around her—although, she is extremely outspoken when it comes to protecting someone being hurt, regardless of if she knows them, or when a friend of hers is less comfortable in a situation. She tends to spend a lot of time living within her own imagination, either through daydreaming or telling stories. She's quite stubborn and strong-willed, and honestly a bit of a know-it-all when the topic is something she's fond of. She likes bows and ribbons and spending time outside, exploring. All of her schoolbooks have flowers (both magical and not) pressed between the pages to dry. She knows how to play guitar, though she’s definitely still learning, and often turns to music as a coping mechanism. She loves to hear stories, but struggles with reading them on her own, so she prefers to have other people read to her. She isn't a fan of the Daily Prophet but is an avid reader of the Quibbler, and spends her summers looking for the creatures discussed in the magazine either in her home city, or traveling across the country on business trips with her father.

The Canvendish family was a simple Muggle family. Mrs. Matilda Canvendish stayed home to care for Ottilie and her younger sister, Imogen, whilst Mr. Cormac Canvendish would often be busy traveling the country for his work in architecture. Imogen was a typical younger sibling, by the fact that she adored her older sister but tended to show it by annoying her. Ottilie takes her looks from her father, while Imogen takes her straight, blonde hair and shockingly blue eyes from their mother. They own a small home on the Bybrook River in Castle Combe in Wiltshire. She was bullied in her younger childhood before attending Hogwarts by the students in their small city (which, admittedly, would be more accurate to call a town or village) for her strange curiosity and sense of adventure, bullying with proceeded to get worse when she returned home from her first year of Hogwarts even more curious and adventurous due to all the things she had learned at the magical school. She absolutely detests bullies and does rather well sticking up for herself, but even though she acts as if it doesn’t bother her, deep down she’s greatly affected and starts to question if who she is is just far too much for people to handle. Because of that experience, she instantly became interested in the subjects of Defense Against the Dark Arts and History of Magic, due to how the former talks of the villains of the past that were terrible to both the magical and Muggle worlds, and the former for providing her with a way to ensure she can protect herself and others from a kind of harm she’s only just starting to learn exists—magical. She dreams of being a bridge between the wizarding world and the Muggle world when she graduates from Hogwarts, and hopes to one day see the two worlds come together, or at the very least see the beginnings of it.

Her first instance of magic happened on a work site with her father just outside of their city, when she was only five years old. A large metal beam from the building they had been working on was dropped from a crane and fell right toward Ottilie. Right before it would have flattened Ottilie, the beam hovered over her until her father ran over and yanked her out of the way, then the beam dropped onto the concrete. Ottilie and her father were the only ones who witnessed the experience, and Mr. Canvendish never spoke of the incident again, until she had received her Hogwarts letter.