My 5 year girl is in kindergarten she is my only child. I am just worried because?

she gets upset and the littlest things at school. She has anaward winning teacher who is increditbly kind compionate and has been doing this over 20 years. Here is my example. I just wanted to check out a PTA meeting and while I was at the school her cl room was open while the janitor was cleaning so I went into her supply box to seee if everything was in tack such as sharpened pencils no broken cryons whatever NO BIGGIE just trying to be a good mom because I know she will not ask the teacher to sharpen her pencil or whatever. Well when I told her that I took the extra bottle of glue so she had more room in her box (mind you she had 2 bolltles of glue and 2 glue sticks) she was so upset and wanted me to cal or e ail her teacher to let him know what happened etc. We even went back to see if the school was still open to put the glue back and it wasnt. I had to convince her that mommy was just trying to help and that next time I will ask and to especialy reure her that the teacher would not be upset. (he is not a mean guy by al means) what do you think is going on here. She is quiet in cl does her work and gets gold stars. This is just one incident she is contantaly worrying. I have e mailed her teacher but did not get a response. I just wanna know how she is "really" doing in cl etc but did not hear from him. Was I wrong? I just so worried about her. Yesterday was the first time when she stood in line with the other kids she felt more social she is very shy but she has the social skills so what's wrong???