Thanks for all for the reply. My friend got an reply from the school that her daughter will need to sit a test in March. If she passes the test but no place is available, the parents need to submit the issue to the appeal panel.
I would suggest contacting another school - maybe Stroud High - and asking the same question. It doesn't matter which school is administering the exam - just make sure the boxes are ticked to share the results with the other schools. As I said, I know that children have taken the Gloucestershire 11+ overseas at the same time as their cohort in the UK.
Query: what the appeal panel will do after that? Help to find a grammar school in nearby county or what?
If taking the exam out of turn (ie, March) the child will not be considered with the main cohort, so is unlikely to get a place if they pass unless the school is undersubscribed.
On going to appeal, if their score is high enough that they would have been given a place had the exam been taken in October, then they would in all likelyhood win the appeal. Unless there happened to be quite a few children in the same situation with higher scores...
Appeals panels have to follow the appeals code. The new appeals code puts a lot of emphasis on academic ability and says very little about mitigating circumstances. Therefore a child with a high score and great academic evidence is more likely to win an appeal than a child with a lower score, reasonable academic circumstances but good mitigating circumstances.
3.13 An appeal panel may be asked to consider an appeal where the appellant believes that the child did not perform at their best on the day of the entrance test. In such cases:
a) where a local review process has not been applied, the panel must only uphold the appeal if it is satisfied:
i) that there is evidence to demonstrate that the child is of the required academic standards, for example, school reports giving Year 5/Year 6 SAT results or a letter of support from their current or previous school clearly indicating why the child is considered to be of grammar school ability; and
ii) where applicable, that the appellant’s arguments outweigh the admission authority’s case that admission of additional children would cause prejudice.
Therefore it would be far better to take the test in October rather than March - getting in without an appeal is the better option by far!