Priscilla Presley, whose romance with Elvis began when she was 14, said Monday it was "difficult to watch" the new movie about their marriage.
She helped director Sofia Coppola during the production and joined the cast and crew for the world premiere of "Priscilla" at the Venice Film Festival.
"Sofia did an amazing job, she did her homework," Presley told reporters.
But she added: "It's very difficult to sit and watch a film about you, about your life and your love."
She also spoke about the controversial age gap when the couple met in 1959 during the rock'n'roll legend's military service in Germany when she was 14 and he 24.
"People think it was sex -- I never had sex with him (at that stage)," she Presley, who is now 78.
"He was very kind, very soft, very loving, but he also respected the fact that I was 14-years-old."
They reconnected in the US three years later and they eventually married in 1967.
"I was really more of a listener, he would pour his heart out to me, his fears, his hopes, the loss of his mother that he never got over," Presley said.
"I don't know why he put so much trust in me but he did."
The film stars Cailee Spaeny ("Mare of Easttown") as Priscilla, and Jacob Elordi, famous as the heartthrob in Netflix show "Euphoria", as Elvis.
It charts the often-rocky relationship up to their separation in 1972.
"It's a human story," said Coppola.
"She goes through all the things that all girls go through growing up... but in this very unusual setting."
Despite their divorce, Presley said Elvis remained "the love of my life".
"It was the lifestyle that was difficult for me," she said. "We were still very close."
"Priscilla" is one of 23 films competing for the Golden Lion in Venice, to be awarded on Saturday.