Who is Lisa from Marley and Me and what is their importance?

Lisa is a seventeen-year-old neighbor of John and Jenny's. She lives with her single Mom who works second shift. One night, Lisa is attacked as she sits in her car in her driveway. The attacker stabs Lisa in the ribs but her piercing screams send the criminal running. John is awakened by Lisa's screams, and he and Marley rush outside to see what is going on. John tries to comfort Lisa while they wait for the ambulance. The two have never met before and Lisa only visits the Grogan house once after her recovery.