Preserve her exact facial identity and exact soft feminine body proportions from the reference image throughout the entire video. She has a naturally feminine, softly toned physique — not muscular or highly athletic. Do not increase muscle mass or muscle definition at any point. Keep her shoulders soft and feminine, arms slim and naturally toned, abdomen smooth with only subtle natural definition, and legs feminine and softly athletic. Her body size and proportions remain unchanged throughout the entire video. She slowly and naturally lowers her arms from the previous stretch and briefly relaxes in an upright position. She then gently shifts her weight onto one leg, slowly bends the opposite knee backward and comfortably holds her ankle behind her for a relaxed standing quadriceps stretch. The movement looks effortless and relaxed. She does not flex or visibly tense her muscles. Throughout almost the entire movement she remains focused on her stretching routine and gazes naturally just past the camera, never directly into the lens. She calmly holds the quadriceps stretch with subtle natural breathing and tiny realistic balance adjustments. Only during the final moment of the video, she briefly glances toward the camera and gives a small, spontaneous, natural smile, as if she just noticed the person filming her. The smile is subtle and lasts only briefly. Preserve the exact denim-blue high ponytail, light-blue sports top, black leggings, skin tone, lighting, camera position, framing and outdoor background from the reference image. No increased muscle mass, no defined abs, no muscular shoulders, no enlarged arms or thighs, no bodybuilding physique, no body transformation, no facial morphing, no identity change, no leg deformation, no twisted knee or foot, no extra fingers or limbs, no exaggerated movement. Photorealistic, feminine, relaxed, subtle and natural human movement.