This is going to sound silly, but if your wife takes one tsp. of locally grown honey a day, it will help her build her immune system up against allergies. It's almost like taking allery shots, but it tastes more yummy.
It has to be locally grown, though. Can't be the processed stuff from the store.
Just a little FYI there for you... (of course, if she's allergic to honey, don't go that route).