your wife has probably been given a "normal tourist visa" as I have in my passport - which means that your wife's passport got stamped, and unless something got specified, it's good for 6 months. It's the same for me.
a visitor record ( from one I understand) is a separate paper, and that can be up to one year. it's mostly given to people who have applications in process, but it's also probably only if you "ask for it" specifically, and/or if the officer decides to give you one. In your case, and mine too, the officer just stamped the passport - which means good for 6 months unless otherwise indicated - and that's it...
Hope it clarifies a bit.
Good luck with your application,
Sweden