https://www.avweb.com/features/pelic...ed-approaches/
Big Pistons Forever. The above link by John Deakin was written many years ago and contains practical advice for light aircraft final approach skills. Deakin makes the valid point that stabilised approaches have an entirely different meaning between a light trainer like a Cessna or Piper and an airliner type. Seems to me having your student call "Stable" at 200 feet is using an airline pilot technique that simply does not make sense when flying a light aircraft that has less inertia and thus more affected by wind changes. A normal approach in a Cessna or Piper single is in the region of six degrees whereas in an airliner it is more like three degrees
Keep in mind the Cessna 172 POH states under Normal Procedures: "Normal landing approaches can be made with power-on or power-off with any flap setting desired. Surface winds and air turbulence are usually the primary factors in determining the most comfortable approach speeds."