I'm so sorry about your friends dad...Freshman year, one of my closest friends lost her father in a car crash. She came to school the next day because she just wanted it to be like anyother day... she was also in denial. From experience, i can tell you that for the first couple days, it's better not to try to talk to her about it. Your main job right now should be to keep her laughing so she doesnt constantly think about her father's death. Over the next couple of weeks, it will sink in and she will most likely come to you. However, if more than a couple weeks pass and she still hasnt talked at all about it, you should probably approach her... bottling up her emotions for that long is never good. Whatever happens, just make sure you're there for her... she's gonna need you.
I hope this helps...