Why don't people lock their damn doors?!
I don't give a crap how small your town is or how safe you feel, locking your doors is ALWAYS the best thing to do. Also never open them unless someone you know has called ahead or you're expecting a delivery. For as smart as Rynn was, she sure lacked any sense or intuition. Also, if someone does threatens you in your home, call the cops immediately.
I just hate scary movies in which the main characters are dumb.