Rachel

This is Rembrandt lighting. The best clue is triangle shaped light on her right cheek.

If Rachel was sitting straight up, you would have Rembrandt lighting with the light source above her and to the right or left. You know the light is in the right spot when you see the triangle of light on the cheek opposite the light source. Since she is leaning, to get Rembrandt lighting the light source is close to straight up and her face is angled slightly toward the light. The light was provided by a studio strobe pointed almost straight up and bounced back at Rachel with an umbrella.