I can't resist when this topic comes up.
My brother married his full cousin. The father of the bride was the brother of the father of the groom. They celebrated their twentieth anniversary a couple of years ago, and they have two daughters. Apart from being unusually smart and beautiful, the girls are otherwise entirely normal.
Yes, it's legal. And their advice on children was that the additional risk was small, given that there are no other known cases of consanguinity in our family. It's when there's a history of inbreeding that the problems start to be more significant.