The flight instructor (CFI) stated that the student pilot flared the airplane too high while on approach for landing, and he instructed her to conduct a go-around. The student responded by applying engine power, but did not lower the airplane's nose. The CFI assumed control of the airplane "too late," and the airplane subsequently stalled and impacted an unoccupied airplane parked near the runway, resulting in substantial damage. The CFI reported there were no mechanical malfunctions or anomalies of the airplane or engine that would have precluded normal operation.