K.N.
Your ideas are great, a chart worked really well for my kids. I don't ahve any expert advice that you don't seem to have thoguht of but i did want to say that my daughter did the same thing. she went from loving daycare to screaming when i dropped her off after being there for about 2 years. i was confused and so terribly upset aobut teh whole thing, luckily nto only did i completely trust my provider but my older children were there and even they said everything was fine, dd wasn't having any problems or getting into trouble and woudl stop crying shortly after i left, so i just dealt with it and it passed, there was little else i could do as a single mom of 3 at the time. so it could just be an age thing and like you said once her friends are with her again she'll probally be fine. best of luck.