The best explanation I can muster for answering this question is this.
Yes, Yon Povi' is a real live flesh and blood person, but more than one, some of whom are breathing some of whom are not.
That doesn't actually answer your real question, does it?
So, what do I mean?
I would begin by asking you. iIs Atticus Finch real?.
Is Greggory Peck more real than Atticus Finch?
Then I would ask you.
What makes a person?
Do you make your Grandmother's potato salad? Do you have her eyes?
I think you can see where I'm going with this.
So to satisfy the most nitpicky among you, I'll say this.
Yon Povi' is a conglomeration of a very real person with the addition of influences from those who have gone before her, and walk alongside her now, just like you.
Are you real?