It is understandable that you arrived at the conclusion that all actions might be involuntary based on your observation of a woman coughing in her sleep. However, there is evidence that contradicts your theory. For example, research has shown that humans have the capacity to use conscious thought and override reflexive responses. An example of this is the research conducted by the Institute of Cognitive Neuroscience at the University College London, which showed that humans can control their automatic responses by exercising cognitive control. Furthermore, there is evidence that suggests that humans can learn to control their reflexive responses and modify their behavior. This evidence suggests that humans do have the capacity to make voluntary choices and act independently of reflexive responses. Thus, while your observations may lead you to conclude that all actions are involuntary, the evidence suggests otherwise.
