My college sister.
I care about you, and I don't want you to study badly. Just drinking and smoking. You were too annoyed to talk to you before. She also has her own life, so she can't stay with you all the time, so she can only be cold to you. I hope you can calm down and face the reality, understand? Everyone pursues their dreams. What you should do is to support her instead of holding her back, so just apologize and express your blessings now.