DD(16) took her first set of mock GCSEs last Dec - she had injured her hand during a football match and had two fingers taped up on her writing hand. So she was put in a separate room with a computer to type her mocks and did better than she expected.
Currently doing a second set of mocks, with everyone else in the main hall, writing instead of a computer and has found it much harder.
So would I be unreasonable to encourage a fake injury in May?