I have always considered 10:00 pm - 7:30 am the window for her abduction.
I realize they believe because of the wet shower, her clothes neatly laid on the bed (which sounds odd to me), and other things that she had slept there all night then was getting ready for work making it early the next morning. There is no indication of when she actually took a shower. She could have been interrupted during the shower or while dressing for work. I guess no one could figure what clothes she would have worn to work on that day according to what was missing from her wardrobe. (Her boyfriend or coworkers should have been able to help out on this, imo.)