EXCLUSIVE: Katie Holmes on how Suri influenced her directorial debut: 'I know myself better because of her'

Katie Holmes' directorial debut,All We Had, tackles the timeless story of a mother's relationship with her daughter, which Holmes says "every mom can relate to," and is one reason she was so excited to helm project.

While this is her first time behind the camera, Holmes also stars in the emotional drama as a struggling, impoverished single mother of a teenage daughter who tries to get her life back on track by moving to a small Midwestern town.

"The mother-daughter theme [of] that unending love that you have for your mother and for your child is universal," Holmes told ET during a sit-down interview on Tuesday.

NEWS: Katie Holmes is Totally Twinning With Suri in Adorable Instagram

Holmes also said that her own daughter, Suri, helped her understand the dynamic between her character, Rita, and her on-screen daughter, Ruthie, played by 18-year-old Stefania Owen --which is why Holmes honored her 10-year-old little girl with a "special thanks" at the end of the film.

PHOTOS: Katie and her daughter together

"She gets a special thanks for everything, [for] every job I do, because she makes every day great and awesome and better," Holmes, 37, shared. "I know myself better because of her, so she'll always get a special thanks."

The Kennedys After Camelot star also opened up about her decision to try her hand at helming a feature film, explaining that she's "always wanted to direct."

WATCH: Katie Holmes Shows Skin in Super Tiny Denim Minidress While Filming at Walmart

"It's taken a long time to take the risk," she said. "I feel fortunate because I have a wonderful support group around me."

Holmes, who welcomed Suri in April 2006 with ex-husband Tom Cruise, recently hit the town in New York City with her little girl for a weekend of bonding and Broadway performances. Check out the video below for more on the fun mother-daughter outing.

All We Had opens in theaters Dec. 9.