Thanks guys! I like the idea of putting them together in the nappy bag - that would help I think.

FWIW the one and only time my MIL changed one of my kids, I showed the the way the AIO worked and which was the front - and she put it on back to front
This made me remember when I was unexpectedly in hospital when DS was 6 weeks old and MIL came to help DH overnight. They were putting on a terry flat and MIL says "where are the nappy pins?" DH says "she definately doesn't use nappy pins", MIL "No, there must be nappy pins for the nappy" (This goes on for a while). And they ended up putting the cover on over the flat loose. (The secret: I used snappis but DH couldn't remember this!)

I've got more questions about flats and covers, but I'll start a new thread I think.

THnaks everyone!