Hi I saw you posted this awhile ago so I hope you get this message. I too have a 5 yr old who is transitioning. WHEN SHE COMES HOME FROM SCHOOL SHE HAS TO TOTALLY LET OUT HER STRESS.
I ALSO HAVE SEEN HER LOOK SERIOUS AT SCHOOL VERY OFTEN.SHE ALSO HAS BEEN TO THE NURSE THREE TIMES SO FAR WITH LITTLE THINGS. I AM NOW TRYING TO VERY CALMLY ROLE PLAY WITH HER AND COACH HER ON TALKING WITH A SMILE ON HER FACE. SHE CAN BE WHINY AND THIS IS THE YEAR TO WORK THROUGH IT. THEY REALLY DO MATURE THIS YEAR WITH OUR HELP.I ALSO HAVE A SECOND GRADE DAUGHTER WHO WAS NOT THIS WAY AT ALL. BUT I DO SEE HOW MANY OF THE KIDS MATURED BY THE MIDDLE OF FIRST GRADE. AFTER ALL, IT IS ABIG CHANGE TO HIT THE BIG SCHOOL! GOOD LUCK TO US BOTH!!

You child is feeling unhappy in the setting. She is not 'spoiled' as you put. A child cannot be 'spolied'! She is trying to maintain her territory and personal space (example - other kids stuff too close to hers). It is just a little bit much, too soon. You indicated that she was previously shy - and this behaviour fits in with her behaviour. She may simply find 'school' a little overwhelming. I am not surprised she does not smile. She may not be sure what she needs to do - even if the teacher thinks she has explained it to her very clearly. It is possible that your child may have certain cognitive functions that are above the level she is working at - this means that the simplistic instructions the teacher give can become confusing because your child is trying to do her best and work at a higher level - this causes confusion. As to complaining - well, we all have our own personalities. Let her complain. If she has something to complain about she has the right to be listened to - just as adults do. However, adults do not like children to complain because most adults want children to meet the adult wants and wishes. This means that when a child complains - the adults complain that the child complains - it becomes a vicious cycle.