Good luck. My EX once acted interested and lost all interest when I started to explain the hand rankings. I often played and the only thing she ever wanted to know was "how much did you win?" She was always planning how to spend the money while I was on my way home. I learned quickly to shade the truth on the amount. She never asked how much I lost.
My advice (notice I said EX so take my advice with a grain of salt) is to compare to a strategy game that she might enjoy, monopoly, sorry, etc. Something with variance, the games I mentioned involve dice so chance is a part of the game. Then throw in the mental aspects. Don't be too involved, just an over view to start. Explain that the strategy and risk create an excitement that you enjoy.
That's my advice.
Good luck.