Starting to become a challenge and not sure what to do

6 yo girl everything that is discussed she says I've done that, after a few subtle questions it us clear she hasn't! I think she does it to have sense of control. She likes to try to dictate what we do and when. Eg what's for snack, I say crackers apples, I don't like that can we have toast. No it's crackers or nothing. Now other children I want toast. Or can we go home yet? No not yet we are waiting for xxx she says oh I want to go!

Becoming a problem as other children are getting annoyed with her. Ok me too!
One child going to French class - she says I've done that I didn't like it Spanish is better. I say we'll give it a chance maybe you will like it. Other child now put off as thinks its bit very good.
I've tried saying to her 'other children don't like it when you have your bossy head on' no change.

Any suggestions what I can say, how to deal - trying to be nice but feel I need to be firmer and more direct with her. She is a smart cookie and age 'gets' things quite easily.
Should I tell parents?