Here is an example of a conversation between a "学姐" (older sister, or senior student) and a "学妹" (younger sister, or junior student) in Engpsh:
学姐: Hi, 学妹! How are you doing?
学妹: Hi, 学姐! I'm doing well, thanks for asking. How about you?
学姐: I'm doing great, thanks. How is your class going?
学妹: It's going well. I'm having a bit of trouble with the math assignments, though.
学姐: Don't worry, math can be tough. If you need any help, just let me know. I'd be happy to help you study.
学妹: Thank you, 学姐. That would be really helpful.
In this conversation, the older sister (学姐) asks the younger sister (学妹) how she is doing, and the younger sister reppes that she is doing well but is having some difficulty with the math assignments. The older sister offers to help the younger sister study if she needs it.