Spidermama. Sorry to hear your friend has had bad news. Do they live just outside the DS/V catchment? If there are inside then there might be an argument in appeal as furrycat says as when B&H changed the admissions policy they said they would make adequate provision for places for people in catchment.
If they live outside catchment, then I'm afraid it is unlikely they will have grounds for appeal. In B&H to appeal successfully, you have to shown that the authority did not follow its admissions policy. If they did, you have no grounds even if the school they have allocated is miles away/rubbish etc.
I assume they have been allocated PCC by your description, or possibly F? If I got either of those two I would be crying too. However, just because the situation seems wrong for many reasons, it doesn't mean they have grounds for appeal.
The other problem is that while your friend may be on the waiting list, I understand it is decided by the same criteria as the original admissions policy so they will always be passed over if there is a looked after child (for eg) or someone new to the area who lives closer who applies for a place.
It is truly rubbish. There is such a difference in quality between schools in B&H.
Unless your friend can prove an admin cock-up (which is v rare, but might include home-school distance being measured incorretly), then she is unlikely to be successful in appeal, no matter what pressure group she joins or what book she buys.
She might get lucky and get a place via the waiting list, but depending on where they are, that is unlikely.
Most likely chance of getting a place might be moving closer to the schools, but obviously there is a time delay on that, aside from all the obvious other issues that raises.
Not sure what you can do tbh. It isn't one of those situations that is likely to 'all come right in the end'. Your friend may have to accept her child is going to a shite school, or look elsewhere - Lewes?, or move .
We were well aware of this and so made our decision about where to live based on secondary catchments before our children were even at school. Seems crazy, but in B&H you have to play the system
Good luck and let us know how it goes.