Is she simply closing the appointment or is she hitting “save and close”? I tried opening a public calendar appt and when I hit “save and close” it told me I did not have permissions to edit the item and asked if I wanted to save a copy in the default folder. I chose to save and it put it in my default calendar. When I simply hit the x and closed it instead it did not prompt me to save it in my default folder. Have you watched her do this to see how she is closing them?