what should i do

Sorry to hear that your sister is acting this way. Perhaps you can talk to her and try to help her to see what is really important. And if that doesn't work maybe in time she will learn herself what is important. Many youths at her age feel and act as she does. I hope that things will work out well for her and you as well.

First how old is your sister? Is she hitting an age where they start to experiment with make up and hair colour, and all that stuff. All girls go through it and they go through an awkward stage where they believe they are the most popular and most beautiful. We all do in our own ways. I am sure this is just a phase that your sister is going through and she'll eventually outgrow it.

she needs a reality check! too many people are caught up in the lives of celebraties. she needs to focus on her own life. i think you should sit her down in a calm way and be honest with her. better the truth comes from you than someone else.

I assume your sister is a teenager? I think it's normal teenagers are insecure about themselves, like to belong to the group and show interest for what they look like. This includes make up and clothes as well. It's hard to fit in the group and make people like you. In this case the only thing you can do is tell her she doesn't look great with that make up and give her a hand, help her with her make over. If you can't do it find someone who can do so and show her how she can look nice/great with make up without over doing it. Burning her down to the ground will have the opposite respond from what you want. Show her she is a great girl, there is no need to be a sheep in the cattle and that only if she looks great and can be herself she will make friends.