P.M.
There's always a reason for any behavior, even if it's not clear to us what it is. Your daughter doesn't seem to have any real idea why this is happening, either, since she gives you different answers each time.
I'd guess your daughter is anxious about starting kindergarten. Would you be able to get to the library and check out a couple of books on starting school? There are some cute kids books about what the process is like, and how common those worries are. Or play-acting, maybe with puppets or dolls, might give her more confidence. My grandson loves to play school, and gets a chance to address all sorts of issues when we pretend.
Knowing that other kids are probably excited and worried, too, and that grownups will understand and be kind to her, might relieve the problem.