Our argument was simply that all the evidence showed that the test result didn't reflect her true ability. The panel thanked us for our honesty at this point and I felt that they must get quite tired of hearing weak excuses for a child's shortfall.
That is one of the most succinct statements, and most truthful, that I have ever seen on the Forum about the reasons that a child did not perform on the day. Well done to you Maggie for having been entirely honest.
Panels are used to hearing the most extraordinary excuses for 11+ near-misses. You can go back over this section and find some of them for yourself. It is up to you to decide if there were any genuine reasons why your child did not perform on the day, but if there were none apart from nerves and tension, then just say that.
I muddled my own appeal by going in to all sorts of convoluted mitigating circumstances. If I had concentrated on the academic evidence my son would almost certainly be at a GS now. (Just give yourself another kick, Sally-Anne!)
I am not the successful appellant that you want to hear from, but I have posted before that I think those of us who appealed and didn't succeed are probably of more use. We went wrong, and we know why. Those who succeeded probably haven't many clues as to why they got lucky!
Apart from Maggie, who has her feet on the ground, that is!
I wish you luck.