You can call the doctor to find out exactly what was in the shot, as this is something you should know. Also, ask for what you should be doing and what you should be watching for and when to call the doctor etc.
Try alternating Motrin with Tylonol. You can ask the doctor what is the rule of thumb for timing when alternating those two. I know you can give them a lot closer together than two doses of just one of those meds, but I can't remember how close together.
Also, try the classics, like a warm (not hot, not cold) bath, cool washcloths to the forehead, see if she will eat any popsicles of any kind or any watery foods like canned manderin oranges or watermelon. The doctor is right, the food is not critical, but keeping her hydration level up is. When my son is very sick, I even let him drink sugary juices, which normally are off-limits, just to keep his fluid levels up.