Who is Billie Bridgerton?
I went back a generation for Because of Miss Bridgerton. Sybilla (Billie) Bridgerton is the older sister of Edmund Bridgerton. She is mentioned (although not by name) in “Violet in Bloom,” which can be found in The Bridgertons: Happily Ever After.
Edmund is away at school during Because of Miss Bridgerton, but we can expect to see him as a secondary character later in the series.