The Enterprising Emigree — Sarah J. Waldock

Recently-orphaned émigrée, Francine DuChesne, is happy to leave school and live with her adoptive aunts, and is disconcerted when her French cousin turns up, insisting that she write to his father, her uncle. Francine consults Viscount Kit Rookwood and his friend, Stotham (Stoat) Brierly about her concerns, and finds herself embroiled in intrigue far beyond the plotting of pranks she used to enjoy at school!