For the unit paper I made the biggest mistake analyzing the wrong text for 15 minutes then realizing so I had to rush it so much spending olny roughly 10 minutes on each question.
But it's a good thing I found out could've lost me 10 marks.
Btw tell your sister not to sweat it too much for the report,I know she deserved those top grades but she'll probably come out with a pass because there was loads of people in my school not knowing how to set out a report and a lot of people did stuff like a formal informal letter and review. About 15 people told me this happened to them and I'm sure there's many more so I'll tell you not alone .