I am now copying work from school books to support the appeal. Could anyone tell me how much I should send and what subjects would be best, I am assuming that I am best with literacy, maths and science?
You should not send schoolwork with the appeal papers, only other evidence. You need to take original schoolbooks, not just selected pieces of work with you to the thearing. You then hand them over at the endof the hearing and the panel take a few minutes to look at them once you have left the room.
I am inclined to keep the letter that goes with the appeal form quite brief, all I can really say is that she would be best suited at grammar, here's her work and her headteachers report. Should I say any more, go into more detail?
I suggest you take a careful read of the Appeals Q&A (link at the top of the page), especially Sections B & E.