Some reasons your wife farts so much can be due to lactose intolerance, eating certain foods, a sudden switch to a high fiber diet, or even irritable bowel syndrome or other digestive system disorders.
Your wife may have also swallowed more air than usually or have eaten foods that are difficult to digest.
The reason old people fart so much is because of natural metabolic changes that take place during old age which include general slowing of the persons metabolism, decrease in muscle tone and less effective digestion.
Farting everyday is healthy and perfectly normal and some people fart everyday and others may fart a few times a week or so depending on their diet.
While excessive flatulence can sometimes mean you have a health issue it is not always the case.
Farting everyday is perfectly normal in most circumstances.
Sometimes I'll fart everyday for a month and then not fart at all the next month and it's normal.
Not everyone farts the same amount or the same amount of times and some people can go a month or two without farting and then fart everyday or every other day.
It all depends on how much gas you have in your stomach and what foods you eat as well.
Although sometimes excessive farting can be cause for concern and if you continue to fart everyday and it doesn't seem to stop then seeing a doctor is a good idea just to be safe and get checked out.