A Daughter's Choice by June Francis
Seventeen year old Katie is about to discover a devastating family secret...
Katie is the apple of her mother's eye and is being groomed to take over the family business. But when Celia, her natural mother, re-enters her life, her world is turned completely upside down.
Tormented by her divided loyalties, Katie is plagued by a question Celia refuses to answer - who is her real father?
(Note: Originally published as Somebody Else's Girl)