my girl also cried in the first week. she yelled and stuck on the floor refused to get change. I was so worried. she only cried for 1 week. I think she is the shiest kid in the world, I have never seen a kid as shy as her.
I sent her to school the first month. when she took school bus the 2nd month, she didn't cry at all and was so happy.
don't worry, some kids may cry as long as 1 month. give her and yourself some more time. you have to ignore her crying and don't take her home from schoolbus. she has to grow up and learn to be independent.