How Do I Handle Nepotism And Unfair Work Environment?

My boss decided to hire a long time friend to join our group since then he gives her preferential treatment and this new hire is not competent for the role at all. Constantly making mistakes after a year and a half of training. in addition to that frustration because of her constant mistakes I have had to correct them all. We apparently now have a new policy per my boss, that any kudos we (I) receive will now be shared by the entire group. Clearly this is wrong..right? How do I handle this without being fired?

Dear GS,
Good Morning,
First of all do not loose your cool,
always remember that if you keep your mind cool you will be confident always.
and confidence moves mountains.
wait for the right time to strike,
and when right time comes,
hit the iron when it is hot,
and remember,
hit first, hit hard & keep hitting,
till you reach your goal.
but do not let yourself loose your temper till right time comes.

What you can do depends upon how large the firm is and how much influence you have within the orgnisation and whether you are indespensable or not.