Thing is, that she texted her friend that it would take her ten minutes to get that badge, that would have to mean driving because it is impossible to walk from where her car was located and back in ten minutes. Driving, yes, walking, no. Her friend waited for her until 7:30am. Why would the friend wait, if she knew that Cheryl would be walking? Although Cheryl did mention to go on without her that she would take a bus and maybe get a ride home with her that evening?
Lots of questions, with probably some simple answers if we knew some of those answers.
IMOO.