Runaway Bride by Jane Aiken Hodge

‘An heiress, and a damned bad hat of an uncle. Look after her, George.’
And so George Ferris makes a vow to a dying soldier to wed his sister. Honour-bound, George resolves to keep his promise.
But Jennifer Purchas has other ideas. Desperate to get away from the money-hungry clutches of her Uncle Gurning, Jennifer refuses to marry a man she has never met. Determined to start her life anew, she runs away and assumes a new identity.
Acting as a penniless governess, Jennifer tries to keep her status as a rebel heiress under wraps. But as mistaken identities and misunderstandings abound, fate seems to have a way of intervening. Will Jennifer be able to live the life she wishes or will her life be decided for her?

*Runaway Bride was first published in 1976.