3 Books Found

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"A story about twins one raised white and one raised black separated at birth. It was a Double Day book sent to me as part of the monthly book club. Read the book back in the 80's or 90's. The white twin did not know she was black and raised in upper white class family. The black twin was raised black and was a singer in night clubs. The book published in the 80's or 90's. They meet and black sister is sick and the white twin replaces her as the singer until she becomes better."