How long has this person worked here? In Canada we have a three month period where a person can be terminated and there will be no legal issues. Why was she not terminated then?
Also, everyone has their talent. There must be something that she does alright. There has to be.
One last thing. There will be millions of times in your career when you feel someone is not pulling their weight but you are not in a position to do anything aobut it. IF you focus on it, you will loose your mind
Just let your chef handle it. Dont rely on her for anything and maybe even work like shes not even there. Eventually she will get the message. If not, well, its just her time shes wasting.