Ooh, I want "The Action Heroine's Handbook" too. That would be awesome.

Does your wife already have an emergency whistle or pepper spray? How about one of those kabutons (provided she will know how to use it), or other type of concealable defensive weapon?

What I always liked to find in my stocking are favorite toiletries and makeup that I'm running low on. The good stuff can be pricey, but often you can find it in travel sizes. Really good makeup brushes are of similar calibre to artist's paintbrushes (meaning that quality really makes a difference).

That's if you want to go the girly route, of course. Really, sharp pointy things are great, too!