How to let a friend know she can't always get what she wants?

How do you let a friend know that she cant alwys get what she wants.
She thinks that if she screws up or stands up a freinds that it will be ok the next day, and im trying to show her that its not by giving her a taste of her own medicine, but she doesnt see what im trying to do! And I cant tell her because she wont listen to me!
I love her as a person but she just takes it to an extreme level.
What should I do?

First tell her even she doesn’t want to listen if she doesn’t care then don’t give her attention just ignore her then she will notice that.

Some people will never learn. All you can do is explain to her in a very precise manner that what she's doing is wrong. If she doesn't listen, MAKE her listen. Stand up for yourself and get what YOU want.

oh jeez, I used to have a freind just like that. I was in 5th grade then, so I had absolutly no clue how to deal with her. anyways, right before I was about to rip her head off because she was SO obnoxious, my mom deceided we were going to move. I hope you figure out a healthy way to tell her. :D

ingore her and she will notice the silent treatment.

Hmm I have a friend like this. I've started learning how to say no... Also I've learnt to stop relying on them... I know its annoying, but some people are self centered and selfish, and if you want to keep them around then you learn to stop expecting stuff from them...