It's your 17 year old neighbor, Beth. She's always been dissatisfied with her life, and her aggressiveness has ended up chasing away everyone close to her. When you moved here, she became infatuated with you from afar, and see's you as her one chance at happiness. Beth has always been scared of actually making an initiative, as every time she talks to you she ends up pushing you away or making you uncomfortable, and has finally decided to take matters into her own hands, so she can be with you once and for all.