I am so sorry to hear about your wife. I know how awfully scary it is and how concerned you must be. My wife wasn't in a coma but she was unconscious for about the first 5 weeks. Just a couple days after her coiling she spoke 4 or 5 words and even joked a little with her face and gestures. It went downhill from there.
After a little over 4 weeks they moved her out of intensive care and into a long term acute care hospital. They didn't hold a lot of hope, it turns out. THe doctor at the LTAC gave her some medicine for narcolepsy and it seemed to pull her back.
I hope you and the medical team are doing all you can to stimulate her and give her familiar sounds and faces. My wife still remembers some of what happened when we didn't know if she knew. Call her. Call her every day and don't be afraid to be loud - reach inside of her. Give her something to come back to.
I don't know if it will work for your wife but it did for mine.
We're still in the hospital. 8 and a half weeks now. But she's finally in an inpatient rehab hospital, just since yesterday,, and learning to walk and function again. It appears that all her muscles are working and her mind gets better every day.
I will tell you that it is painful just to type this to you; I know the pain you're going through - and I didn't have to go through it as long as you have. I'm not an unreligious person but not terribly religious either but I will tell you that I will be praying for you and your wife because I know your pain so well.
Just never give up on her. Fight for her. Fight with her.
An interesting note is that as my wife begins to recover her mental faculty, it turns out that anger is a great stimulant for the brain. :) She gets mad at the world, or even at me, over things no one did or can control - but when she's angry she becomes much more clear in her speech, her logic (even if misapplied due to her condition), and her alertness.
When she was out, I begged her, I cried to her, I was stern with her. I told her how much I needed her and had to have her back.
After she began to wake up, and before we knew if she was going to recover her mind at all, they put a speaking valve on her trach. Much later that night, I begged her again to come back to me... She just laid there. I went to the sofa in the room where I slept and then heard her say, "I need you, too." Can you imagine how I felt?
We have a long way to go yet. She's still very confused and mixed up and has a very hard road ahead physically but we will likely be home in 3 weeks and working through the rest on an outpatient basis.
I hope your story ends as well as I know ours will. Don't give up. Don't ever give up.