As a retired Neonatal Nurse who has been involved with the transfer of extremely ill babies on countless occasions and who has also seen the way the RFDS Kingair is equipped, I am sure that it would have been impossible to accomodate all the equipment and staff necessary in the one aircraft. The incubators themselves are very big and heavy requiring very strong anchorage and I'm sure the retrieval team will have consisted of a minimum of one doctor and one nurse per baby plus all the portable equipment required. The incubator when fully equipped weighs around 16 stones. It is usually fitted to a standard ambulance trolley to which are attached various pieces of medical equipment such as infusion pumps, cardio-respiratory monitoring systems and large gas (air and oxygen) cylinders. Even if it were possible to squeeze it all in it would leave little or no room for sufficient access to the babies should they require any medical intervention en route.
I tried to find a photo for you but couldn't.)