I'm not sure I understand your question, but I'll make more clear, or expand on what I was saying, and see if it answers what you are asking.
There never was a nanny named Zenaida Fernandez-Gonzales. Casey told her parents that a woman by this name was taking care of Caylee while she (Casey) was at work. She also did not have a job. She has not worked since sometime in 2006. There was no job, there was no nanny. She made it all up.
Caylee was beginning to speak, and someday down the road, it would have been reasonable to expect that someday when Casey brought Caylee home, Cindy would ask Caylee if she had fun that day at Zenaida's house. Caylee would have said "who? I was with Mommy today at some boy's house" or something along thoses lines.
So eventually, Caylee had to be removed from the picture, or Casey's gig would be up. Her family would find out that she did not have a job.
Casey was into boys. Caylee was baggage she didn't need holding her back from them, and partying. I believe that she planned it in advance, as evidenced by the searches on her computer for how to use chloroform.
When Cindy found out that Casey had stolen money from her (Cindy's) mother they had a huge fight. I believe that Casey snapped then, and ended her baby's life the next day.
Out of anger and jealousy.
Was that what you were asking about ?
I agree that Caylee's beginning to talk was becoming a problem to Casey, but I'll take it even further, especially considering children absorb everything from adults around them.
There's obviously a lot of agression issues with the Anthony's: we see it with Cindy (i.e. throat around Casey, dealing with protesters), George the former cop and Casey (the lone exception is Lee, who prior to Casey was an only child - being in the same position, I'm sure he's the peacemaker, just like I am). So you have Caylee absorbing all of what she hears from these folks - not just the Father's Day argument, but the argument that must have happened a week earlier (June 8 when Casey was kicked out of the house). So what if Caylee popped off at her own mother (since everyone else seems to be doing it - like Cindy and the folks at Fusians when she took caylee there and they told her it was inappropriate to take a child there). So Caylee could have said any sort of thing to set off Casey for an instance that would have resulted in her death. Like "you're not my mommy".
People have been talking about the chloroform, the pool, burying bodies and the possibility that Caylee may have died on the 15th of June. I think you have to look at a clear timeline of events and a bit of simple logic. To assume Caylee died on the 15th is to assume Cindy deliberately lied about tucking Casey and Caylee that night - and that George deliberately lied about seeing Casey and Caylee leave the next day. During the 911 call and when police were first involved, Cindy told some untruths, but I think we can agree that it was more confusion that deception - otherwise, why even call 911? She earnestly wanted to find Caylee and really didnt' know what was going on. We can hear that on the 911 tape. But she does clearly mention June 9 - perhaps forgetting about Father's Day was actually on the 8th, or not wanting to talk about the big fight - but what hits me is that she uses the 9th - she identifies it as Monday. She knew she last saw Caylee on Monday. George swears he left the house alone at 2:30pm on Monday. If he's lying, why that lie? Why say he saw Casey with Caylee arond 12:30pm on Monday? He could have left it open to adjust the story later on, so the whole day is in question. The Anthony's don't close rank until later on, when they realize their daughter may be up for murder and they go into protection mode. So that leaves us with a window of 2:30pm to 3:03 - and we know from the GPS printout tracking her cellphone (discovery p498) that she was near the Anthony home from 12:30 to 4pm Monday.
Then we have the series of calls - 3:03pm to Dad, then an hour later, several calls to Mom. If Casey planned to kill her daughter, why at the Anthony home? Padilla speculates that Casey used the chloro on Caylee, then put her in a pool, then took her out then dug a grave. The problem is: the series of phone calls feels to me like an accident happened and Casey is between true honest panick & genuine fear for her daughter - and fear of being blamed for her death (with her well honed skills of covering up kicking in). Nothing else explains to me why she made so many calls to her parents, especially when she really didnt' want to talk to them after what happened yesterday. And we know that Burner didn't come back from vacation until late that evening - Casey borrowed the shovel from him Wed or Thu, but was there Tuesday. Cindy says she notices the pool ladder next to the pool and the gate open on Tuesday. So we have an incident happening on Monday (prompting the calls); Tuesday - Casey at the Anthony home and possible pool action (but no shovel) - also, GPS has her going to a lake near University Blvd at 4:36 (discovery p498-506); Wed - Casey back at Anthony home and Casey borrows shovel for one hour - burner never mentions Casey being wet and she only uses the shovel for an hour.
So I just don't buy the pool drowning conspiracy. I think Casey had the fight on Sunday with her parents and stormed out of the house without Caylee (perhaps Caylee demanded to stay with grandma); Monday Casey came to pick up Caylee at 12:30pm but simply parked around the corner or somewhere near the house to stalk it until George finally left at 2:30pm. Then she went back in to either chill out or steal some more checks/credit cards/etc - leaving Caylee alone. Caylee swallowed something and died, or Caylee somehow angered Casey (by whining or saying something offcolored to her) and Casey inadvertently killed her (maybe slapping her and she hit her head, or shaking her - you choose). Either way, she died or was dying - panicking, she called her dad at 3:03pm and actually talked to him - but hedged on how serious it was and decided to end the call. That's when she started the cover up plan. Caylee goes into the trunk of the car while George probaby called Cindy to tell her to check up on Casey - Cindy blows up Casey's number but Casey avoids her calls until 4:11 when she tries to reach mom to tell her everything's ok. Next day she goes to the Anthony home where Burner sees her for the first time this week - and Casey may have tried the pool idea but didn't like it and instead goes to the lake perhaps to dump her, but doesn't want to be seen or can't insure the body will be weighed down, so she aborts that idea, puts her back in her car and calls it a day. Next day she's back at the Anthony house and, knowing the Anthony's are renovating their back yard, decides she can control the situation better by having Caylee buried in the yard, hopefully unnoticed while George later on lays concrete. She borrows the shovel, runs into some complications (maybe the bag busts)- I'm also thinking since Cindy removes a knife from the car, that Casey actually dismembered the body - and starts burying her. For whatever reason, she stops and starts this process for the whole week, perhaps always second guessing herself and anticipating her dad finding the body.
By the end of the week, the Anthony's have resorted to following her, trying to find out where she is. Maybe George discovered the body. Maybe the "gas can 911 call" was an attempt by George to get Casey to confess, but he wimped out and decided in the end to protect his daughter. I think George is heavily involved in getting rid of the body. But no one really knows what happened to Caylee initially. But I think it happened between 2:30pm and 3:03pm on Monday June 16th.