Well, it depends on the woman. What size does your wife normally wear? I looked at your link and consulted the size chart. If I were purchasing that jersey, I'd probably go with a size Small men's. (Generally, I prefer men's jerseys and have not had a problem with fit, but women who are more busty might have a problem.) For reference, in 'numbered' women's regular clothing sizes, I'd probably wear something like a 4 or a 6. (5'-5", 115 lb.)
I've come to the conclusion that there simply are no 'cool' women's jersey designs.
Good luck!
It looks like a very nice jersey.