The theory that Casey was actively impersonating a ZG is plausible IMO.
http://.com/2009/01/16/zenaida-gonz...venture-zannie-and-annie-go-to-traffic-court/
Is it then possible Casey truly intended to account for Caylee's disappearance by telling her parents she had handed over permanent custody to Zanaida. That Casey had planned to tell her family she realized she was unable to be a good mother to Caylee, so this was best for Caylee? Zanaida (supposedly) took Caylee to such fun places throughout mid june-July, it appeared Casey may have setting up "it was to Caylee's best interests to be part of Zenaida's life permanently". Possibly Casey had planned to move far away as well, to avoid her family's concern. So if anyone cared to check, ZG was a real person with a vague paper trail, who then disappeared without a trace, taking Caylee.
In this scenario, Casey could truly account for WHY Caylee was not with her, as opposed to the "she went here, she went there with the nanny" stories. She could tell everyone that Caylee was not with her because she had agreed to a legal arrangement with Zanny.
(Could she pull this off to cover for Caylee's death, without an accomplice?)
Instead what actually happened is through her mothers panic, Casey was preempted (although she did beg her mother for one more day) when her mother called the police and all her diabolical plans were not fully in place. (Not to suggest Casey was good at planning) Casey was having too much fun with her newfound life to focus on many details, and her plan needed "time" to work. So at the point CA called 911, all Casey had to hang on to was there was a Zanny, and Zanny took her, simply because that was only as far as she'd got.??