Yep, you've probably guessed it from the title. Cut it in half with a big pair of scissors. Looks easy. There are what look like pockets on the duvet to contain the feathers. Easy I thought. Sew another line close to one of them, and then cut along the middle. Ta da! Two small duvets, just the right size for a baby bed.
Nope. Not that easy. The pockets are not sewn right through both layers of duvet cover. That would have made the duvet too flat. So when I cut through: Ta da! Explosion in a feather factory!
Much muttering and stapling of edges (temporary) and binding with ribbon (permanent) later, and I am now the proud owner of one nice fluffy baby duvet and one slightly less fluffy baby duvet.
In the picture, you can see the little duvet with its nice spotty cover I made from an old piece of fabric I've been saving. In the foreground is the lovely vintage stripe rescued from the cat and now given a new home.