Hi Ken,
No, Family Sharing and iCloud Drive are two completely different things. First of all everyone should have their own iCloud account for things like Mail, Contacts, Calendars, Reminders, Notes, Drive, Photos, Documents etc., which is fortunately the case.
With iCloud Family Sharing you would add another "layer" for you and your wife, where you could buy content like Music, Movies, TV Shows, Apps via iTunes and the App Store together, which means that you only would have to pay once. But that's not all iCloud Family Sharing offers also the option to share photos, calendars, location more easily (please see here): https://www.apple.com/icloud/family-sharing/
BTW: Shared photo streams as well as the other features can also be used without family sharing, you just would have to set up a shared photo stream, a calendar etc.
With kind regards,
David