Hi,
As I was reading your question, I thought that you are such a very nice husband to her, treats her nice and acts like a gentleman. I do think that there are not a lot of men out there who shows that kind of attention and caring for their wives. So your wife is very lucky.
Both of you are 47 years old. I have a hunch that your wife is on pre-menopausal period and I think she needs to see a Gynecologist to test her hormonal levels. Another suggestion is for both of you to consult a marriage counselor so she will have a better understanding of your dilemma. Perhaps, you both need to see a sex therapist or a good sexologist.
I would like to suggest for both of you to buy a book called "Proper Caring and Feeding of Husbands" and also the "Proper Caring and Feeding of Marriages" The author of the books is Dr. Laura Schlessinger who is a well-known psychologist and marriage counselor. You can get those books at the Barnes and Nobles. You need to read these 2 books together. It's very helpful for couples experiencing marital problems. She has also some radio programs on the AM radio and they are usually aired in the different States. Hopefully you are in the U.S. Her website is: www.drlaura.com.
Other possible causes of your wife's sexual indifference are:
1. She may be upset with you about something that you have done consciously or unconsciously.
2. She may be interested in someone else( hopefully not).
3. Stress from work if she works out of the home.
4. Financial worries( possibly)?
5. Getting bored with the usual routines in sexual intercourse, perhaps you need to be more imaginative and creative.
6. She may have some medical problems or emotional problems
7. Depression
8. Drug addiction( less likely)?
Please try to find out the reasons why she changed her attitude to sex. You need to have an honest open discussion about the things that are bothering her.
Take care and I hope you will get into the bottom of this.