Nice job Eliza.
My question is whether or not it is plausible Casey discarded Caylee's body on this day. Here are my thoughts:
At approximately 11:45 she runs out of gas and pushes the car into the Amscot lot. Amscot is 15 to 20 minutes from her parents, depending on traffic / lights / etc. Cell activity supports her leaving the area around 11:25.
Question is, did she leave from her parent's house or somewhere close by at 11:25?
Note that ping 6 hits on a tower near the Carter Glenn Condos, followed by a hit on the cell tower near the junkyard. The junkyard cell tower is pinged frequently from the Anthony's home, but the Carter Glenn Condo tower was rarely pinged from there during the latter half of June (the pings are more frequent there during the first half of June, and they are bounded by pings at the other two cell towers near the parent's).
My guess is that she probably did leave her parent's home at ~11:25, although it is possible she was nearby in an area south-southwest of her parent's.
Now, when did she arrive at her parent's? With respect to ping 3, she is at most 10 minutes from her parents driving south from Tony's, so we can assume she arrives around 10:45. Therefore, she is at her parent's and/or in the vicinity for about 40 minutes.
She spends at least some time rummaging around her parent's, because she grabs some food (AL notes in his interview that Casey has it with her at Amscot, and there really is no time for her to make a grocery stop anywhere). She may have also rummaged through their mail, found the JC Penney card, and called to activate it.
Rummaging around takes some amount of time. The call to JC Penney pings a tower north of the Anthony's consistent with many call made from the residence, so she is probably still at the home at 11:10. This leaves just 15 minutes to discard Caylee's body, if that is in fact what happened then.
The text to AH suggests that may have in fact happened. If so, she could not have travelled very far from her parent's home, and the body would probably not be far from a road nor would it be buried. There was not a lot of time to do any hiking or digging.
It is possible, too, that the body was discarded in a nearby dumpster during this time. I do not believe the dumpster would be at the Amscot, because she texted AH prior to running out of gas and referred to the 'dead animal' being plastered to her car in the past tense.
Thus, if Casey discarded Caylee's body on the 27th, I believe it had to occur in that small window of time. This should mean a relatively small search area near the Anthony's and the body would not be particularly well hidden...unless she used a dumpster. The body would also be wrapped in something, because the trunk was pretty clean and Casey was too when AL picked her up.