Isn't she unpleasant? It's obvious, after a little conversation, that she's not going to cooperate with you without a little pressure. We need more info here. Who else is there who might know something about her that we could use?
Hint 2
The only person is Adrian, the RA, so go talk to Adrian and ask him everything.
Hint 3
Kelly told you that JoAnn slept all night. However, Adrian tells you that Kelly doesn't sleep in the dorm most nights. That disconnect is significant, but Rosa needs a little help to draw the obvious conclusion here. That means it's notebook time.
Hint 4
Click on your notebook (in the upper left corner of the menu) and click on "JoAnn slept all night," then on "Kelly sleeps elsewhere." This gives you a new notebook item.
Hint 5
Now go back to Kelly and click on "Did Kelly lie?" After this, she'll be slightly more cooperative, so ask her everything again until she repeats herself.