What is a ward in Bridgerton season 4?

• Bridgerton Season 4, Part 1, introduces Benedict's love interest, Sophie Baek, who first appears as the mysterious 'Lady in Silver' at a masquerade ball.
• Sophie, the illegitimate daughter of the late Lord Penwood, shares a dance and a kiss with Benedict at the ball before disappearing at midnight, leaving him with a single glove.
• Her backstory reveals she was raised happily until her father married Lady Araminta, who knew Sophie was his daughter despite him calling her a 'ward'.
• The dictionary definition of a ward is “a person, especially a child, who is legally put under the protection of a law court or a guardian”.
• After Lord Penwood's death, Lady Araminta left Sophie nothing in his will and forced her into servitude as a maid in her childhood home.
• Sophie's surname was changed from Beckett in the book to Baek in the series to honour actress Yerin Ha's Korean heritage, a decision made by the showrunner.