My friend is in a coma & I'm confused about a few things, can you please help?

My friend has an illness that caused her to go into a coma. A coma is when a person is unconcious & not responding to pain, sound or anything for more than 4 hours right? Correct me if I'm wrong, but that's what the medical staff said. Well she was like that for about 24 hours maybe 36. Then a few hours ago she woke up, looked at me, said something like she recognized me and stuff and then she ped out again. So she was awake for like 2 minutes not even. So is she still in a coma or not? The medical staff there is pretty rude & I didn't want to ask them much. Is this normal for someone in a coma to slip in and out? Or is she awake from her coma now & just sleeping? I'm so confused. Please only answer if you're a little familiar with comas and stuff like that. I'm pretty worried. Thank you.