Respectfully, I disagree with that, if you listen closely to the 911 tape, Cindy is yelling to someone (presumably George) that Zanny took Caylee..
I was floored by the "familiararity" with which she said that name, so much so that I initially thought it possible.. Listen again, whoever she is yelling to she must have thought they knew the name as well.
I do not believe Caylee ever had a "zanny" but I believe there is a reason they knew that name, whether they were writing out checks to her because Casey was telling them she needed the "sitter" money, Casey stole checks made out to her and that's how it was explained, etc..
Or she was looking at apartments to move out with a fake ID and possibly had an excuse as to why mail might come to that house in that something..