Before you do anything, do you know if she'll be upset if you change her name? You do have a right to your own name, but it wouldn't be nice to upset her by changing it without her permission.
Perhaps you could ask her about changing her name? Maybe you can all take turns having a name you like for a period of time. Or maybe you can talk to the admins about having your own account so that you can have your own name and passwords and stuff. What name would you like to use?
I'm sorry you think that no one does as good of a job as you do. But, then, I guess it's a good thing the system has you to help them out.

(Sorry, I'm not trying to be mean in anything I say. I'm a bit "fuzzy" right now). Maybe you can ask to cook more often? Or maybe you can even have a day where you do all the cooking? It never hurts to ask.
I certainly hope you feel better (you seem to be a little down), and I hope you get this figured out. *hugs if wanted*