Well, a friend of mine, that's also here in menewsha, suffered an accident about two months ago and went into a coma, and hasn't woken up until now...
I was informed she is in a grave state, and that it's probable that she remains like that for some time.
And I don't know what to do, if there's any way of helping her or anything else.
I'm really worried, since I was with her when that accident happened and only got my leg broken.
Is there anything I can do for her?

If she's still in a coma and you can't get to the hospital then you can always record a message or get some of her favorite songs together and put them on a CD so it can be played to her. IF you can't think of anything to say then you can always find a childhood story and read that.

Then I'll read her a book... But doing that shortens the time she'd have to stay that way?

No one knows for sure, at least the last time I heard, it was said that it's impossible to tell if that helps a person wake up or not. But depending on the severity of the coma, there are certain things that she could be aware of, so in case there's a chance she is even slightly aware, even if it doesn't help her wake up, it could help to hear a friendly voice, to be acknowledged.

That's really good to hear. Thank you, HIM_ROCK and NeuzaKC.

Have hope for her, believe that she will get better.

The brain works in strange ways, even if it takes a little longer than everyone would like for her to come round if she doesn't rember you being there at least you will know that you were there for her and that will be important to her that you didn't abandon her.

And never feel silly sitting there reading to her.

I know how it is... My best friend is in a coma too, so I go there every week to say hello and stuff like that...
And yes, I heard it really helps those in a coma if you talk positively to them, put their favorite music(s) on or even do things they enjoyed before.