My parents adopted a younger sister who was born in a scholarly family. Her father is a university professor, and her mother is superior to her in the high-level family of state-owned enterprises.

First, you have to find out why your parents adopted her. Then she had a good family condition. Why is she willing to be adopted by your family?

And you also said that she didn't like rural people from the beginning when she came to your house. Maybe her family conditions are too good to understand the sufferings of the countryside, which is one of the reasons why she is not close to you. Now that she has graduated to find a job and got married, the conditions of an officer can be said to be very good. For your family, you may not really be accepted as a family with you in her heart. Maybe you just kindly let her go to school, but

The above is my personal opinion. Through what you have said, you can learn more about it in combination with the actual situation.

Good luck with everything.