Yes, but what about the reverse? Can Aeris exist without Sephiroth? I would say so. But again, if she is still around, I don't think it has anything to do with Cloud. Just as a uniquely powerful half-Cetra.
Where Aerith is depends on your opinion of Sephiroth's fate. Nomura has directly said, "as long as Sephiroth exists, Aerith must exist". So if Aerith is gone, that means the threat of Sephiroth is gone as well. If he endures, Aerith endures as well.