Aunt Jane's Nieces on the Ranch by L. Frank Baum

Inez found Miguel Zaloa smoking his cigarette among the orange trees. He was quite alone and looked at the girl in an expectant way as she approached.

"Oh, Miguel! " she cried. "I tell you a secret. Of course it is no secret any more, for now they all know it, up there at the house. Meeldred Travers, the girl from New York, is not Meeldred Travers. She is the child of Leighton the smuggler -- she is Meeldred Leighton!"