Miss Jacobson's journey - Carola Dunn

'Improper and impious!' her family crimes, but in most unladylike fashion, Miriam Jacobson defies her parents.
Finding the thought of marriage horrifying, she rejects their suitable choice of bridegroom, choosing instead a life of adventure and travelling to the continent to join her physician uncle in his work.

Following on from his death and the outbreak of war, Miriam decides it's time to go home.
To secure passage to England, she accepts a patriotic mission from the Rothschild banking family, though it means enduring a lengthy journey through France and Spain in the company of two insufferable gentlemen - one an intolerant aristocrat and the second a member of her own faith who seems to dislike her and yet is somehow disturbingly familiar...