Hi, I'm really sorry that this is happening and for what you must be going through. I had a similar experience with one of my best friends a few years ago. He was found unconscious in a very similar state after mixing alcohol with opiate painkillers. He was in ICU for 2 months on a ventilator with a serious lung infection and was also kept in an induced unconscious state because doctors were worried he might have had brain damage from the lack of oxygen he experienced in the hour or so leading up to when he was found. I visited him nearly every day for weeks and it was horrible seeing him that way, the worst part was not knowing the extent of the damage, if he would ever recover or even if he would wake up, the doctors didn't really know. But he was OK in the end and made a complete recovery. It took a long time in hospital for the lung infection to heal and for him to breathe on his own, but when he finally did there was no brain damage and after a few more months he pretty much went back to normal.
During that time I felt completely powerless. But I tried to support his family as much as I could - they were the ones going through an unimaginable amount of pain. You just need to have hope and make sure you talk to those closest to you about what you're going through right now. Even just visiting and holding her hand, talking to her, letting her know you're there I think makes a big difference. You might not think she can hear you but deep down all the sensory stuff is there. My friend responded to me sometimes when I talked to him and I never gave up on him getting better. Hope this helps and you keep accessing the support you need, whether it's your friends, family or the family of your friend, or even just finding support from others on this forum.