Meredith left the house of Robyn Butterworth at about 20:55 on the night of Nov. 1. She walked with Sophie Purton for about 5 minutes, then left Sophie to walk the rest of the way to the cottage alone. This would also be about a 5 minute walk. Knowing that she was killed at the cottage, it had to have been after 21:05.
I should also mention that the car park camera picked up an image of a female figure crossing the street to the cottage that night. The time given by the police for this was 8:43, but they were assuming the clock was 10 minutes fast. Taking the defense position that the clock was 10 minutes slow, the time lines up with when Meredith returned to the cottage. Look at this location on Google Maps and you will see the driveway for the cottage is right across the street from the parking lot.