Some pple like to throw their weight around when they have authority over other pple. Most pple like this have no self worth. They lack the feeling of importance in thier life so they make it up by "bulling"pple. The way I see it is you have 3 options
1) Talk with the dean.
2) Ignore the way she puts things and remember you can't control what other pple do.
3) Confront her in a appropriate manner and discuss it.

I hope this helps some. If ya need me I fot your back I will take her on! hahaha j/k