Going to the chapel (or indeed the civil ceremony)

That's all the talk in our house at the moment.
My sister gets married in nine weeks. We are currently trying to figure out the appropriate music for her civil ceremony. While she laughed heartily at the suggestion that she walk back down the aisle to the theme from EastEnders (Think about it "I now pronounce you husband and wife" cue dramatic drum roll....) I don't think she will go for it.
Being with child she has herself suggested "Knocked Up" by the Kings of Leon - but perhaps it won't set the right tone.
I'm useless for other suggestions. I had a big old fancy church wedding (eight years ago this month) and my music was largely religious. I walked down the aisle to a string quartet playing 'The Minstrel Boy'. Had everything from The Song of Ruth to Amazing Grace in between and walked out to a very happy 'This is the Day' song which had us all bopping in the aisles. (Canon in D was in there too, while were out in the sacristy signing the register, so I missed it).
All suggestions welcome.

And just for show, this is the version of The Minstrel Boy we had at our wedding..