More importantly, in the process of communicating with him, you should infiltrate some things that parents have paid a lot of effort and effort for him from time to time. He probably doesn't know your parents very well yet, because he is devoted to your parents and refuses. So it's not easy for you to make him realize his parents' difficulties. Maybe this way, she won't reject your parents too much. I remember my adolescence, but I won't think so when I grow up. I will gradually feel the hardship of my parents and see their sincerity.
So if you want to open your sister's heart and give her a psychological consultation, you must choose to treat this problem equally, neither too high nor too low. Whatever it is. I hope your sister can open her heart and communicate with your parents, and I hope you can give him better psychological counseling.