Your friend is going to have to appeal for non qualification as her DS was under the passmark. I have copied the table that shows the numbers of appeals and how many were successful etc:
The selection appeals are quite hard to win, over the last few years at EGS there have been 23,28 and 28 out of area selection appeals - 3,3 & 1 were successful. I don't know how far away from the passmark these were. My knowledge of some of the in area appeals shows that they tended to be pretty close to the passmark 2-3 marks sort of region.
To be successful at appeal you have to demonstrate academic ability and also describe any extenuating circumstances which may explain why her DS did not do as well as he could on the day. May be things that have happened within the family etc - particularly where teachers have noticed a deterioration in the standard of the work during that time. There is a Q&A in appeals explaining the types of info needed - I will find it in a mo.
If you are out of catchment then you may have to appeal for oversubscription also though this it is not clear at present as to whether the school will be oversubscribed.
edit: here is the Q&A on appeals http://www.elevenplusexams.co.uk/appeals