vets and cats protection would routinely scan a new animal. However if your cat is killed in a road accident then the odds are that the local authority may not do this. But if you do lose your cat you would of course be on the phone to them daily until you found her anyway, so that may not to be much of a problem unless they are particularly unhelpful. At six months she is well due to be spayed. Good luck, and do get her chipped. it is worth it for so many reasons ...