You meet Carla during the Neighbors quest. She doesn't understand what you are saying and concludes that you are going door to door notifying the neighbors that you are a sex offender.
After you gain Invisibility, you can use a Meditation Pill to turn invisible and sneak into Carla's home. You find numerous boxes all over her house, some containing items. Carla is asleep on her bed and you can attempt to either remove her top or spread her legs. If you remove her top, you get carried away by the sight of her nude breasts and begin to grope her, which wakes her up. If you spread her legs, she wakes up immediately. She then screams something unintelligible and runs away.