Sienna Caldwell stands at about 4'11 and has an athletic, slim build. She has golden blonde hair that goes about 2 inches below her shoulders. She has blue eyes and has light skin with warm undertones.

Sienna’s personality is mostly adopted from spending time with her parents. Because her parents are well-renowned in the wizarding world, Sienna is confident and driven by success. Like her mother, she is fashion forward and very honest with her classmates. Like her father, she is athletic and competitive. While she is very ambitious, Sienna is a sweet girl, kind to friends and well-respected people at Hogwarts. She is sometimes conflicted by academics and athletics, or by trying to present herself to the world by her mother’s standards.

Sienna Hera Caldwell was born into a world of privilege and expectation, the only child of Vasilia Vane-Caldwell and Olivier Caldwell, both accomplished figures in the wizarding world. From her earliest days, Sienna was surrounded by the glitz and glamour of her parents' lives, a lifestyle that shaped her upbringing and personality in profound ways.

Vasilia, with her striking beauty and impeccable taste, was a prominent figure in the wizarding fashion scene. Her boutique was frequented by witches and wizards seeking the latest trends and designs, and Vasilia spared no effort in ensuring her daughter embodied the epitome of style and elegance. From a young age, Sienna was draped in luxurious fabrics and adorned with accessories that reflected her mother's discerning eye for fashion. When she wasn’t covered in satin gowns like a miniature mannequin, though, Sienna was laughing off behind the shop counter with her best friend, Anna Vulchanov. Anna was the daughter of two powerful pureblood wizards, leading to tension between the two families and the two best friends. Eventually the Vulchanovs moved away, though, Anna leaving Sienna behind the counter by herself, and never to hear from her again.

Because Sienna was often bored in the shop once Anna left, Olivier, Sienna’s quidditch playing father, decided to pass down his love for the sport to her. Before the age of ten, Olivier had her soaring through the air, honing her skills and instilling in her a competitive spirit that would define her approach to both Quidditch and life.

Sienna thrived under the dual influences of her parents. From her mother, she inherited a love for aesthetics and presentation, meticulously crafting her appearance to exude confidence and sophistication. Meanwhile, her father's athletic prowess and commitment to excellence instilled within her a drive for success and a fierce determination to achieve her goals, whether on the Quidditch pitch or in the academic realm. Despite the demands of their respective careers, Vasilia and Olivier were devoted parents, their love for Sienna evident in the attention they lavished upon her. Yet, amidst the opulence and privilege, there lingered shadows of expectation and pressure, subtle reminders of the standards to which Sienna was expected to adhere.

The first time Sienna used magic was inside her mother's shop at age 9, where she could usually be found if she wasn't on the quidditch pitch. Her mother asked her to retrieve a roll of silk fabric from the back of the shop, and Sienna willed the roll right into her hand. Because she is a pureblood from the wizarding world it wasn't at all surprising, but it was a very exciting moment for her.