As long as the TV has an audio output jack (maybe with a headphone symbol on it), any simple headphones should work, even cheapo walk-man headphones (though some block more sound than others out the sides of the earphones). Also, most earphones have a pretty short cord, so you probably need an extension.
Now whether or not she can use the phones, and you can listen to the same TV on it's regular speakers at the same time is the big question. With some equipment, plugging in phones disables the TV speakers, but I dunno about new fangled equipment. And there's the volume issue; she may need the phones up too high for you to listen to the TV speakers at the same time, if they will both work at the same time.
Time to look at the back (or front) of your TV, and pull out the instruction manual (and if you go to the store, take the manual with you).
I think I'd find a cheapo pair of foam walk-man phones (5$) to experiment with before I did anything else.**
This is all cords, I know nothing about wireless.
**

I hated the guy on the airplane/subway who used these next to me, you had to listen to whatever he listed to.
I am similar to Pavlov's Dog, you play rap music next to me, I automatically want to kill you.