Being a mom taught 'Won't Back Down' star Maggie Gyllenhaal 'secret things' As a mom, Maggie Gyllenhaal knows what it's like to have to stand up for her kids -- and in her new film, "Won't Back Down," she was able to channel that energy as a mother fighting through bureaucracy to help her children get a good education. "The person that I play in the movie ends up being kind of a hero," she said during a visit to TODAY's plaza on Friday. She really does risk everything for her daughter's education and ... I wanted people who saw it to feel like they could make that kind of change, too. And being able to have that motherhood experience -- Gyllenhaal, who is married to Peter Sarsgaard and is the sister of Jake Gyllenhaal, has two little ones -- gave her extra insight into the role. "Once you're a mom, there are like these little sort of secret things you know," she said. You know that in your pocket you'll find a bag of Cheerios. ... Little secrets that you just wouldn't know otherwise. ... This kind of way you can kind of fight for something you otherwise wouldn't have known. Also, there's this whole spectrum of feelings that I just didn't have until I had my girls. "Won't Back Down" opens on Sept.