Greg,
I have heard that major illnesses, even those that are conquered cause depression. When you are depressed its hard to feel anything. In that case counseling may help her. I am experiencing something similar, I thought I was there for my husband and he said for a couple of years he felt something missing, that special something we had is not there. I analyzed this and determined to come up with the reason realized that I had focused on my career to the point of neglecting him. His business slowed down and I was in a position to take on more clients. The business slowing was also highly stressful for him and could possibly go under due to the economy. Then it turned around, he got busy, too busy and that too was stressful. I thought I was supporting him taking off the stress but it was the little things that he missed. He'd want to go to bed early but I was too busy working late at night, he'd buy me little gifts and I'd distractly say thanks. I thought I was doing the best thing for my family and I missed out on so much. I can't say I did anything wrong...financially its what was needed but there are a few times I could have said to heck with it and dropped everything. I missed several camping trips, but its the daily connection. Things are turning around now and its been a lot of work but I am a better person now, one thing that helped me to learn what to do and how to reconnect is Mort Fertel's program
Marriage Problem Solving Program Producst & Services another good one is Dr. Ellen (advertises on this site see banner). I would suggest you look in to these and learn how to reconnect, make her fall in love with you again. Good luck.