Missing Kitten from Stillwater Apartment Complex (South Hill)

I have a sibling set of kittens and one of them disappeared. My son found them out on a rugby field a few months ago and brought them to me and I have been caring for them since. I have put a lot of money into them and they have a vet appointment this Saturday. Her name is Lightening and she does have a harness and name tag on. I have trained them to be inside/outdoor cats and I suspect someone swiped her.