If everyone normally is expected to do the practice papers then, yes, you could argue that.
In Bucks, in the old days [and for the old test], when people hadn't done the 'familiarisation' then 5 marks were added to the score to compensate.
Do the school reports make it clear she is 'well above average'? Will they give any predictions for the KS2 tests?
It would make it a lot easier if they would add marks to compensate! I will make sure to mention the fact that she was the only one not to sit the practice papers.
The supporting letter the school sent to support the appeal stated the levels she is working at. Her head teacher and class teacher are attending the appeal with me to answer any academic questions so I hope that will help.
Many thanks for your help