Julie's sisters Phone
How did copying her sisters phone give them her location. The sister didn't even know where they were going. How stupid was she to let them in to begin with.
shareIt was a little confusing, but I'm guessing that, by copying the sister's phone, they were able to acquire Julie's cell number, and, once they had that, they were able to track Julie's phone.
The sister was definitely dumb, but, I think, in this instance, Bob Lee and his wife were dumber. She never should have brought her phone with her, but, rather, she should have either purchased a disposable phone or have been given one by Bob Lee prior to leaving.