I'm going to call my sister out for procrastinating
Why do you want to call your sister out for that?
I don't like it when someone delays the important things that needs to be done
It is okay to call out your sister especially of she is missing the important things. You can help her out and give tips on how to manage time.
You don't understand, she just needs to get it together.
I just think you could help her with getting things done in a timely manner. Perhaps she doesn't realize how bad her procrasination hurts others around her.