The Mississippi Court of Appeals earlier upheld the conviction.
Young appealed on issues surrounding evidence of his prior sexual misconduct, as well as testimony from a sexual-assault nurse examiner.
While various justices disagreed in degrees with the overall opinion, written by Justice George Carlson, they affirmed the Union County conviction and Court of Appeals decision.
Young was sentenced to life in prison.
In a split vote, some justices objected to 20-year-old testimony from a half-sister, saying it was too remote in time to show a propensity.
Others objected to the nurse’s testimony about the cause of the female child’s injuries.