Our daughter is marrying a non-Christian

As a Christian father, should I give my daughter away at the wedding if she's marrying a non-believer? Over the more than twenty years of our marriage we've worked hard to raise her in the nurture and admonition of the Lord. Her decision has come as a great disappointment to us. We love our daughter, but for us this is a question of conscience and faithfulness to biblical principles. In light of what Scripture says about being "unequally yoked," should I, as her father, support this marriage by "giving her away" at the wedding?