I'm not going to share my inheritance with my sister
Why are you not going to share with your sister?
She can take care of money well, I need it more
I completely understand the need for money and struggling financially, however the inheritance is meant to be shared and your sister deserves her portion. Perhaps you could speak to her and she can give you advice on how you can manage your portion well and make your money grow.
Yea, she can work a good job someday. There's nothing wrong with keeping it all and buying what I want.
If the money was left to both of you, then you should share it. It is going to hurt her to know that you are trying to exclude her from her fair share of the money.