“Star Wars” gave Carrie Fisher her defining role. Now 59, the writer and actress returns to the franchise in “The Force Awakens,” which opens in two weeks. The movie, the seventh in the series and the first since 2005, has already broken records for advance-ticket sales. The wave of product tie-ins started in early September, a far cry from what Ms. Fisher remembers from when she first played Leia in 1977. “More merchandise than I can imagine,” Ms. Fisher says.

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