I used to put individual diaper changes in one of those throw away diaper bags (poor for the planet, but what can you do.) Diaper, ziploc bags of wipes. That made getting in the tiny loos easier. Onboard if you will not fit in the loo for changes, ask the cabin crew where you can do the deed. Also pack way more diapers than you think you could ever need, babies seem to liquify in the air.