A Lady and a Scholar by Wendy May Andrews

After her rich husband’s sudden death, Lady Evangeline refuses to remarry for convenience–especially not the handsome but cranky mathematician helping her gain financial independence. Sean Smythe has good reason to hate all things English, especially ones with titles. But when the lovely lady asks for his mathematical help with her economies, he can’t help but say yes.
But when Evangeline’s in-laws start a fight over her inheritance, they fight dirty, even dragging Sean’s history into their scandal. Despite her wish for quiet independence, her sense of justice won’t allow her to let Sean fight the battle for her.
As her alliance with Sean grows deeper, Eve is forced to choose between newfound wealth or one last chance at the happiness and love she never realized she craved.