My wife, the facebook princess says.....
(she did it for us)
1st goto Profile
Then click on EDIT PROFILE under your photo
goto RELATIONSHIPS (under profile pic and above likes and intrests)
Then there should be a field labelled Realtionship Status,
Choose accordingly, and then underneath that, there is a"box" You can use to twrite her name in.
and then you can also add your anniversary.
Go all the way to the bottom and click SAVE CHANGES (blue button)
For her pic to show up, she has to accept your relationship request.
And that will do it automatically for you.