VH-MLE, again my deepest sympathies for your family's misfortune - if life was just and fair then this is indeed totally unjust and unfair.
obgraham (as the real expert in this field) has given an excellent explanation and slim_slag's assessment of the screening techniques is indeed "spot on".
You say, "....I am finding it very difficult to not blame the doctor that did her last pre-diagnosis pap smear for the mess we are currently in". Your reaction is very understandable, but there is no indication that anything was done wrong, and as obgraham has tried to explain, it is not at all impossible that your wife should have progressed from a normal pap smear to invasive CA within 14/12.
It's a bit like a man who has a clear check for colon cancer one year and is diagnosed as having invasive colon cancer the next. Most cancers spend quite a long time at a very treatable stage (that is why screening tests like pap smears and colonoscopies are useful), but a minority start and progress so quickly that they are just not present at screening. It is very likely that this was the case with your wife. You also need to rememember, amidst your shock and grief, that it is not the doctor or technician who gave your wife cancer.
I am not a trained counseller, but I have spent more than half a lifetime dealing with newly diagnosed cancer patients, particularly women with breast cancer, so sadly, I know very well what I am talking about. Elizabeth Kubler-Ross classified the 5 stages of grief - the first is Denial (it can't be true), the second (which you are struggling to cope with) is Anger (why me/her?). I very strongly suggest that you seek counselling to help you manage this most difficult time - I am quite sure your wife's primary gynaecologist will be able to connect you with someone who will help. Your reactions are perfectly and completely normal, but you need someone to assist you to understand your feelings and help you deal with them.
Getting stuck in the early stages of grief will eat you up and destroy the many chances of happiness together that you still have, so please please, get professional counselling NOW - it won't change the situation, but I promise that speaking your heart to someone who truly understands will help immeasurably.
Mac