Buffy coughed into her hands and noticed tiny dots of blood on her palms. It wasn't a particularly pleasant sign. If she hadn't been coughing she would have told Fred to stop. Her shouting was going to bring more around.
When she saw Jesse come out, she waived them off. Buffy started to stand up when her vision blurred. Her arms went out for balance. But her intention became clear with the first uneasy steps. The slayer intended to put as much distance between herself and the church as she could.