The heartfelt film tells the story of a World War II messenger boy who experiences pain, love and hope through the telegraphs he receives, and is based off of Pulitzer Prize-winning author William Saroyan’s 1943 novel The Human Comedy.
Quaid, 20, plays her son in the movie, and Ryan, 54, tells PEOPLE Now it was “fantastic to have him around” the set, especially as he loyally helped to calm any jitters.
“We were lucky to get him because he came from Martin Scorsese‘s set of Vinyl … and I said, ‘Oh, Jack, our set is so dinky and small compared to Scorsese’s and he goes, ‘Oh, mom, mom – it’s the same.’ So it’s good to have a son who will say something like that.”
While directing might seem like a challenge with family members involved, Ryan insisted that Quaid’s supportive presence and her real-life role as a mother were positive influences on the film.
“[Motherhood has changed me] fundamentally,” she said. “I have two kids – I have Jack who is in his 20s now and my daughter who is 11 – and I think that part of my life served my [ability] to direct the best.”
Of course, it also doesn’t hurt when Tom Hanks shows up to help.
“He did such a wonderful favor,” Ryan said about her longtime friend and costar in the film. “He showed up with his big spirit and happy self – I still can’t get over it! He flew down for a day and was so gracious and happy and the whole crew was so excited to see him. It’s a wonderful thing he’s done.”
This is the fourth film they’ve appeared in together – after Joe vs. the Volcano, Sleepless in Seattle and You’ve Got Mail – and Ithaca has them reuniting onscreen for the first time in 18 years.
The duo have gotten to know each other pretty well over the decades, and Ryan doesn’t hesitate when asked to name the quirkiest thing about the beloved star.
“I can’t get over how much he likes the water!” she confessed with a chuckle. “Just being on the water in any way. It’s an adorable thing and I don’t know why I’m saying that but it just seems like he’s attracted to water.”
Ithaca is available on VOD and in select theaters now.