"To be able to connect with the person that you're sharing a role with is huge," Ferrer, who plays a younger version of Lively's character, tells PEOPLE Gotham/GC Images believes her costar is "an angel." Ferrer recalls exclusively to PEOPLE about when she first met Lively and what it was like to portray the actress’ younger counterpart in the new romantic drama. When Ferrer, 24, met Lively for the first time, she thought, "This is the most beautiful woman I think I've ever seen in my whole life," she tells PEOPLE at the Tuesday, Aug.

6, premiere of the film in New York. “Then she greeted me with the warmest hug ever, and from then on, it was just wonderful warmth and friendship.” After describing Lively as “an angel,” Ferrer says, “To be able to connect with the person that you're sharing a role with is huge, and she's just a really good person.

” She also notes that both women “understood that support is so important, especially through a process like this and especially with a book like this.” Lively stars as Lily Bloom in the film adaptation of the 2016 novel of the same name by . Ferrer, who previously starred in an episode of , plays a younger version of Lily.

Raymond Hall/GC Images Ferrer also tells PEOPLE that what surprised her most about Lively, 36, is “how she manages four children with the businesses that she has and [her] career as an actor and a producer and everything else.” Lively and husband share James, 9, Inez, 7, and Betty, 4, and son .