That would be a nice thing to have, Wilma!
Unfortunately, SmartCopy doesn't have any way to tell if there will be a "duplicate" show up from among the 100+million other profiles on Geni -- until after the profile is created. One just has to be diligent about checking the "family" surrounding a profile before deciding they may indeed be duplicates -- or not.
You may have noticed the small "magnifying glass" next to the Parents section of SmartCopy; that is a way to perhaps a little more conveniently search for the parents on Geni before creating a new set of parents for the current "focus" profile.
Of course, if you haven't seen it yet, if there is a existing Geni "Tree Match" (e.g. the Blue square) for the current focus profile, SmartCopy *will* tell you that with a reminder to check it out before creating more new profile (you can then come back to SmartCopy to check if any fields need updating or profiles added after dealing with any possible duplicates).