I have the same size wrist. 16cm
I tried on a friend's RO diver in black. It is way to big. Even if you buckle on the last notch of the strap, the watch will wear very loose. It wont feel secure and will be swing and rotate around your wrist. Which won't feel comfortable at all. If you are doing anything active, the crown will bang or dig into the back of your hand.
As for looks wise, still way to big to make it look good. You will look like a kid wearing a grown up watch. there is no way to make this look good with someone that have under 16cm wrist. With rubber straps, the watch should look like it fits securely to look good. Girls can pull off larger watches but there is a limit. For a <16cm wrist women's, I say a 40mm is largest I would go.