The Orphan Heart — Natalie King

It simply could not be true. Yet with her own ears blonde Karen Mitchell had heard her mother, Marion, confess that Karen was her niece, not her daughter, and that Alicia Blake, the dark, vivacious cousin so like Marion, was in fact Marion's daughter and not her niece. Suddenly Karen had to think of herself as Alicia Blake and adapt to a new way of life and a new family.

Only Alicia's extraordinary talent of doll making and costuming keeps her going -- and eventually leads her to a choice between two very eligible men and to a final proof of her identity.