What promise does Rosa make to Liesel?

Rosa promises to call Liesel if Max wakes up.

“Yes, Mama.” She was about to open the door. “But you’ll come and get me if he wakes up, won’t you? Just make something up. Scream out like I’ve done something wrong. Start swearing at me. Everyone will believe it, don’t worry.”

Even Rosa had to smile at that. She placed her knuckles on her hips and explained that Liesel wasn’t too old yet to avoid a Watschen for talking in such a way. “And score a goal,” she threatened, “or don’t come home at all.”