I disagree with her on the diabetic issue & the CPAP issue. Diabetics won't necessarily die first. Plain and simple, if a person (Type II diabetics) is NOT eating, they just need to stop their meds (oral OR insulin) and just watch what they consume VERY carefully. Restrict their diets to mainly proteins and they will get by. The first week will be the toughest because the medications needs to eliminate from their systems.
As far as the CPAP, most people don't NEED them in order to survive. Sleep apnea is often caused by being overweight (usually Obese). If these folks can make it through the first month, they'll lose weight and the sleep apnea will eventually subside.
The biggest thing will be food rationing. People will have to ration their food VERY carefully. Many of the city dwellers that rely on the grocery stores (then there's the folks that think that meat comes from the grocery store) and have ZERO hunting skills will be most at risk.
IMO, the first that will die are the robbers & looters. Those that have guns will be able to protect their assets, whereas those that don't will be at their mercy. Don't try to steal, rob, rape or otherwise engage in criminal activity and "you" probably won't get killed or injured. Plain and simple, if someone with ill-intentions comes on MY property, they are likely going to die.