I know a friend who has the same condition. It's nothing to worry about as long as they're all connected.
I have had three kidneys all my life (two on the right side, the third is slightly smaller than the other two), and I function just fine with no issues. It is nothing to worry about, they all work fine, and I have a spare that I can donate if family ever needs it and still have two for myself!
I'm hearing it for the first time....Is this really possible???