Billie Lourd's role in “Last Showgirl” reminded her of Carrie Fisher and Debbie Reynolds (exclusive)

Filming The Last Showgirl was more than just a job for Billie Lourd.

During an exclusive conversation with PEOPLE at the Toronto International Film Festival (TIFF) on Friday, September 6, the Booksmart The 32-year-old star reflected on what it meant to her to play her role in Gia Coppola's film.

“It's so weird, a movie about Vegas and mothers and daughters… could I relate to that? 100 percent,” jokes the actress.

Billie's mother, Carrie Fisher, died in December 2016 at the age of 60, and her grandmother, Debbie Reynolds, died a day after her daughter at the age of 84.

Lourd says she “fell in love” with Coppola's script the first time she read it because she connected it to her family history.

“I was so excited to be involved in this because it reminded me so much of my mother and grandmother,” she says of Fisher and Reynolds. “My grandmother was a showgirl herself and my mother was a little bit of the character I got to play.”

“It was really cathartic and incredible to be in that movie and play that role. It was really cool,” she adds.

Lourd stars opposite Pamela Anderson's Shelley in the film. According to TIFF's official synopsis of The Last ShowgirlShelley “tries to reconnect with a daughter she barely knows” (Lourd) after learning that her job at the last traditional show on the Las Vegas Strip is ending.

The attempt at reconciliation “proves to be as difficult as the loss of the only job she ever had,” the synopsis states.

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According to the Neon Museum in Las Vegas, Reynolds signed a historic million-dollar contract to perform during the Christmas season at the Riviera Hotel and Casino in Las Vegas in 1962. Fisher and her brother Todd also appeared on the show with their mother.