Yes, it is indeed amazing that Cindy didn't take action before the day the smelly car was found. I really do get what you are saying. Yes, most of us would never let a child be in danger without taking drastic action.
However, I believe there is more to the story than confusion and denial. IMO there are deep dark secrets in that family -- treachery and evil -- and there are reasons why for instance, Cindy didn't simply report that car stolen right away, or at least prior to "31 days" in order to locate her grandbaby who was with someone she knew to be a thief, liar, sociopath, spiteful b*tch, and unfit mother.
I'm not saying she knew Caylee was deceased prior to July 15, but IMO she feared for her safety and wellbeing all that time ... and she DID know (IMO) once the car turned up smelling like death.
And totally agree about not admitting anything incriminating or ugly to others, even if it's obvious to all... she shares that crazy trait with her killer daughter IMO.
JMO