Lavinia Halsworth is a classmate in Marie-Grace Gardner's class at school.
- Name: Lavinia Halsworth
- First Appearance: Meet Marie-Grace
In The Books
Lavinia catches Cécile by her hand at the Children's Ball and rudely tells her not to dance, unaware of the switch between Cécile and Marie-Grace. Cécile simply laughs at her and joins in with the other dancers.
As Meet Cécile is told from Cécile's perspective, Lavinia is not identified by name.