My opinion is still that she either just snapped and hurt Caylee or couldn't risk the rejection she feared more than anything if Cindy were to find out that Caylee died accidently while in her care. I don't think there was a motive other than she was really mad at her parents or really afraid of Cindy's reaction to whatever happened by mistake. I don't think she plans well enough to have motives.
I agree with this. I honestly think that Caylee's death was an accident. I very strongly feel that way. And I think Casey panicked, was in total fear of her mother's reaction, and tried desperately to get Cindy to believe that it was a nanny (of course, one that doesn't exist) because she doesn't want to 1) lose her mother's love and 2) earn her mother's anger.
By the time all the evidence started coming out, I think Casey felt like she couldn't admit the truth, and probably knows she reacted completely in the wrong.
I do think, however, that this entire family, Casey included, loved Caylee at some point and in some way. It's the only thing that helps me get through this.