Arya is one of my favorite characters in the books though too. I've read them all too, and who knows if this scene won't appear in Winds? If we ever get it. I feel like at a certain point I have to separate my idea of the books from the show. I still have faith though, that Martin will not follow the same path with the books as the show is taking, to a point. That is assuming that we get another book before that unhealthy bastard dies on us.
And Arya's line to Walder's wife was really satisfying for me too, considering she was just outside while her family was being murdered by those dicks.