Abigail's Adventure (The Charity School #3)
Sarah Waldock

Uncle Frank and Aunt Caro press gifts and treats upon Abigail who finds their generosity oppressive. Although a bluestocking Abigail is able to help poor Richard when he is unable to cope with the trails of life, giving the boy love and affection.
It is not until Abigail meets Richard’s cousin, Renn, Baron Chisterley, that Abigail becomes aware of the insidious plot that stands between her and happiness.