To follow-up on this and not to pile on, flagging a post isn't necessarily a negative thing. It indicates folks wanted to make sure your question got special attention before you could really be helped by the wider community.
To address your question, it's still not clear what kind of help you're looking for. There exists thousands of resources online (plus likely your sister's course syllabus) on how to get started with R. But pointing out that you could search for those things feels a little obvious and snarky to me (... so I'll say it anyway in the most roundabout and friendly way I can think of... sorry...).
If your sister has a specific coding question about her assignment, I encourage her to ask it. There are lots of people here that might be able to help. How should she ask it? Here's a handy guide to get started: FAQ: Tips for writing R-related questions. Since this is a homework question, you should be aware that this forum is frequented by R-user instructors, and so you should be aware of our homework policy, FAQ: Homework Policy.