Butterfly - I never thought Caylee was supposed to "stay lost".
KC had a situation. A stench in her car that would not quit, even after she got rid her small "problem". She dumped the car in a public lot, on the business side of the street, the car was obviously supposed to disappear - She had dumped Caylee just feet from the road, along a street that gets regular foot traffic, 9 mos a year. Had she left Caylee a month earlier, some little kid with a lot of moxie, would have investigated the odor.
Maybe she didn't realize the odor coming from the side of the road would dissipate, be completely gone (and under water) before school started again. If she tossed the bag from the side of the road, as was theorized, there was no way she could have anticipated that spot filling in with water that lasted for 6 months!
She never thought she would have to come up with a real person, with a real phone number and a real address - it was a private number, lots of people have them (not so much babysitters). She never realized her nonexistent job was going to be questioned.
KC's behavior was totally consistent with a certain type of single, young mom, on vacation - the kid was having a good time with the nanny. Suddenly her baby turns up, deceased and the trusted babysitter/friend is missing! "Oh no! Poor KC, she lost her friend and child in a cruel twist of a who done it." But she was prepared to be strong and to go on with her life, like Caylee would have wanted.
Once it was announced Caylee was missing, there were no tears, no fear - When she realized it made her look bad, to have given her child to a questionable person, suddenly Caylee was taken by force as KC and Caylee played in the park. Then she spent a month looking for Caylee under barstools - she continued with the ridiculous story, that even she would have been hard pressed to believe. Because her original thoughts on the way it was going to go down never happened. CA is not able to change modes. She reminds me very much of a Borderline Personality - but not particularly smart.