What Causes Fever, Coughing, Congestion, Headaches And Leg Cramping?

My daughter isn t feeling well and has a mild fever, cough, congestion, headaches on the sides of her head, and leg cramps. She complains of not having the energy to be active and it hurts when she moves a lot. Any ideas? My son recently had pneumonia and I have thought about that but she complains mostly about the body aches and lack of energy... everything hurts