Lavinia Herbert is the (former) secondary antagonist of Shokojo Sara until defected to change of heart.
Lavinia has grown jealous to Sara as she is the class representative. After the death of Sara's Father, she becomes more spoiled. In later episodes, Lavinia occupies Sara's former room with her family and she does not want Sara to be a maid.
By the end of the episode, Lavinia has a change of heart.
In Live Action Drama
Lavinia is also known as Maria Takeda. After Seira's father's death, Maria Takeda has become more spoiled. By the end of episode 10, she has a change of heart and goes fair and square with Seira for exam. She congratulates Seira for doing exam.