06/01/2012 at 05:55 AM EDT
works hard for her supermodel physique, but she still lets her kids occasionally treat their sweet tooth.
The mommy of four took all of her little ones to the Landmark Theater in West Los Angeles, where the group headed straight to the concession stand and Klum bought her children M&Ms before catching a mid-day flick.
"She seemed in a great mood and very much in control of her kids," an onlooker tells PEOPLE. "She was in sunglasses and it didn't seem like anyone recognized her."
The family wasn't alone, the source says, explaining that there was a man with them who looked like a bodyguard and "kept scanning the room." – Scott Huver