Is a Rolex an appropriate graduation gift?

You are the one who knows your wife and her tastes, so you will need to take that into consideration. I did not like the idea that it was used from the start. I looked at the link you provided and I was not impressed, but your wife might be. I would not want a watch. I would prefer a memorable experience, a short romantic cruise? A romantic dinner? A surprise party? I just think you could get a long more bang for your buck than with that watch. It is an awesome accomplishment, congratulations to her.