After a conversation with 2 friends today we wondered if anyone knew the answer.
This isn't applicable to any of us yet (maybe never will be) and shouldn't be an issue anyway as children usually get in from where we all live.
If you have multiples in Y6 and one has a statement/ehcp naming a secondary school for Y7. Do(es) your other multiple(s) qualify under the having a sibling at the school criteria? The criteria say has a sibling, step sibling etc living at the same address at the school in the September of entry.