which side do you wear a watch
Most woman wear their watch on their left hand too. Sure there are exceptions, but a standard watch is meant to be on the left hand, assuming people are right handed. That way, they can operate the crown on the right side of the watch more easily.
Men usually wear a watch on the left wrist because all classes of men have always dressed themselves. While most men are right handed so it's easy to put on your left wrist. Women of the upper classes were all dressed by maidens so the maid would have put the watch on their wrist.