This scenerio, has played out in my mind many times...
With all information from your work & JamesBondJames, there is only 30 mins. between the call from George to her call to Tony @3:35pm. This is why the premeditation doesn't work for me. We know that there was an argument on the 15th, which is substantiated in the Docs., Supplemental Report, Pg 2499, by Mark F to LE. The basis of that argument stemmed from Cindy's visit on Father's Day, & her conversation with her mother about the checks, & her mother's admonition to throw KC out. I think this was building & festering with Cindy on the ride home & she finally unleashes all of this on Casey, coupled with her being an irresponsible & unfit mother to Caylee & believe it was a huge blowout. Considering this with her all-night activity with TL (very little sleep) & combined with feelings of worthlessness, it explains, why, if an accident did occur, she could not face the fact that her mother was right. If this had been injected into KC's mind over & over again & then it actually happened, here is the Self-Fullfilling Prophecy manifested into reality! I think we can all relate to some incident in life where we've seen this occur, & it is Shocking! Maybe, if this unfortunate set of circumstances had happened without the assault from the previous night's altercation, her course of action after the fact, may have been different.
The cover-up now begins. Caylee is beyond anyone's help at this point & only thru some momentary neglect on KC's part did this occur. She exonerates herself. This is also when she literally "drops out of sight" from her usual group of friends (too many reminders of Caylee) & fills her world with new people & distractions. She does not feel guilt, she is thinking the child is hers to do with, what she deems necessary, for her own survival.
As crazy as this may sound to some people, (including myself) I see young people today, as not viewing death the way previous generations do. Witnessing KC's Facebook & MySpace, paints a fatalistic portrait of her views on life & death. I do not condone, in any way shape or manner, her actions on how she disposed of her daughter, I'm just trying to step outside & look at why or how this may have happened!