“Millicent Simmonds is an extraordinary actress, I mean she really is,” Moore, 56, tells PEOPLE Now.
The duo star together in the big screen adaptation of Brian Selznick’s 2011 young adult novel, which tells the story of two lonely deaf children living 50 years apart.
Moore says that she knew 14-year-old Simmonds, who is deaf in real life, was perfect for the role from her first audition.
“She recorded and audition for [director] Todd [Haynes] and Todd sent it to me and it was clear just from that audition alone that she was incredibly expressive and really knew what she was doing,” Moore explains.
“To have somebody who’s so young, in their first film, be able to do what she does in this film is just extraordinary,” she adds.
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Simmonds also got rave reviews from another major star who saw her film at the Cannes Film Festival. “I was leaving the building and I looked over and I saw Will Smith coming up and I was like, ‘Oh it’s Will Smith, oh my god it’s Will Smith,'” she remembers.
“And then I saw him coming over and he said, ‘I really loved your film, you did a great job.’ I could feel my heart, I couldn’t breathe, my heart was just beating a mile a minute. It was beautiful,” she says.
By starring in a movie that features deaf characters, Simmonds says she hopes audiences will “really recognize that deaf people do have frustrations because of the lack of communication access.”
The actress is also urging viewers to “support the deaf community by inviting them into the greater society … we’re all one big family. Regardless of your disability, we’re all one. And we should be invited into the general community.”
Wonderstruck opens Friday.