The actress told Tuesday's The Late Late Show With Craig Ferguson that she became a fan of White the instant they met on the upcoming Hallmark Hall of Fame movie.
"She's amazing - I love her. The first day when we were in the trailer she didn't say anything to me for the first few minutes. She sort of walked in, sat on a chair and - looking dead straight ahead - said, 'So, what's it like to not be the pretty one in the trailer anymore?'" recounted Love Hewitt. "I loved it!"
The 31-year-old also spoke about the movie, based on the novel by James Michael Pratt, describing it as a "nice, sweet" project. The plot follows a reporter (Love Hewitt) who investigates the story of a woman (White) who has been waiting for her soldier husband, declared MIA, to return for 20 years.
She previously described the film as "one of the greatest love stories [she] had ever read", saying in a press release that it will appeal to viewers of all ages.
"The portrait of the incredible love between Betty's character and her husband Neil back in the 1940s, and the portrait of my character falling in love with their grandson - I mean, those two storylines just come together so effortlessly."
The Lost Valentine airs January 30 at 9pm ET/PT on CBS.