FWIW...some info to use in lining up theories 'bout what happened 6/15...
Per E-Pass records
here it appears that Cindy and Caylee left for Mt. Dora around ~9AM, 6/16 (see Conway toll 9:27AM)
Per cell pings, Casey left G&C's just after ~9AM and arrived @ Tony's ~9:15AM.
Per E-Pass records (and consistent w/ statements) it appears Cindy & Caylee returned home to Hopespring ~3PM (see matching Conway toll @ 2:33PM).
Per cell records...
@ 3:35PM Cindy called Casey's cell from the Hopespring home phone. Casey let this call roll to vmail, and Cindy left a 36 second vmail.
@ 3:45PM Kyle called Casey's cell phone and Casey let this one roll to vmail also. At no time during this period does Casey interact w/ her phone.
@ 5:06PM, w/o checking vmail, Casey called G&C's Hopespring home phone from her cell phone @ Tony's apt. for a 3 minute conversation, or left a 3minute answering machine message.
...2 hours pass, w/ no activity on Casey's cell, @ 7:06PM Casey begins a text dialogue w/ Tony while she is still near his apartment. The pings from this conversation indicate Casey left Tony's ~7:06PM.
@ 7:10PM Casey already enroute & unprompted, calls G&C's Hopespring home phone for a 1 minute conversation or answering machine message.
@ 7:36PM Casey arrived @ G&C's Hopespring home.
...between 7:06PM and 9:26PM Casey is engaged in a continuous texting conversation w/ Tony (and a little w/ Amy). The single greatest lapse between their texts was 11minutes @ 8:56 w/ most of them in the 2 minute range.
@ 9:26PM a period of cell inactivity lasting 39minutes begins.
(IMHO, this seems to be a good candidate for "the fight")
@ 10:06PM Casey ends the cell inactivity after receiving a text from Tony by placing a call to Tony and talking w/ him for 10minutes
(IMHO, this also would seem to be indicative of the fight having just taken place)
@ 10:25PM the heavy texting between Casey and Tony resumes for the balance of the night...with a 40minute break @ 11PM.
Some other things to consider...
IIRC, George was @ work 6/15PM...based on his work schedule he would've been gone or in the process of leaving about the time Cindy & Caylee returned to Hopespring that afternoon.
I believe Caylee's naptime was typically 1-3PM. Since Caylee was @ Shirley's, etc. during her normal naptime, Caylee likely fell asleep in her carseat on the ride back to Hopespring (speculation).
Cindy didn't fire off several calls to Casey to come home. She simply left a vmail. Even when Casey didn't respond. No add'l calls from Cindy.
Casey was casual about coming home. She may have seen the missed call# and known about being called from Hopespring, but, she didn't check her vmail. She simply did her own thing for another couple of hours and called when she was on her way home.
There appears to be an opportunity for Cindy & Caylee to have gone for a swim after arriving @ Hopespring after Caylee, perhaps, finished her nap. Recall they had eaten @ Shirley's. Dunno if they needed to eat again.
By 9:26PM a tired Caylee should've already been in bed asleep. IIRC, Caylee typically co-slept w/ Casey in her room. With George @ work still, and Lee nowhere around, this would've given the rest of the house to Cindy & Casey to have it out. By this time in the evening it would also seem to be quiet enough in the neighborhood that a shouting match would've been overheard...esp. if they carried it out into the backyard...
This scenario would have Casey going into her bedroom (closing the door presumably) with Caylee already asleep after "the fight" if it indeed occurred @ 9:26-10:06PM.
For 6/15 post-fight-smothering theory proponents it would appear Casey had ~35 minutes of cooling off from the time she resumed texting w/ Tony (perhaps in her room w/ Caylee) until a 40minute period of cell inactivity began. Not that Casey would've required more than a few minutes to accomplish a smothering...just that it might entail more than just the act itself. Could also just be something like a time to remove make-up, etc. FWIW.
Hope that helps paint a picture of the day.