Hi, how is your friend doing. I think probably she is under stress both physically and mentally as she needs to concentrate on her studies as full time student and also perform her duties as part timer. This might be causing her physically and mentally exhausted due to lack of proper rest causing easy fatigability leading to such sleepiness, run down feeling and not being interested in any activity. Does she speak of any problem relating to self or family or work place. She needs to do morning evening-walk, stretches, have good nutritious diet with lot of water or other liquids, learn relaxation techniques and have adequate sleep. You can also consult your doctor if she continues to do so. Take care.