How do you know if it's serious?

I have a beautiful daughter who is 7 years old.  She is the most creative and imaginative person I know.  If the imagination and character she shows at 7 is a sign of things to come, she has quite the bright future ahead of her.  However, her skills are almost too honed at 7 years old to be normal. 

My daughter can entertain herself for hours with silly little toys by telling herself stories about them, role playing, and singing. That's great! How wonderful that she can make things up like that! Unfortunately it doesn't stop there.  She tells semi-strangers like her friends' parents or the lady at the after-school programs stories about herself, me, my husband and our lives. Some of her stories are little fibs that may be nothing more than a fantasy, like when she told someone her Grandmother is rich and she gives her hundreds of dollars for her birthday. Some of her stories are out right lies, like when she told daycare that I was a doctor. But here is the thing... she tells these stories with conviction. If you didn't already know that I wasn't a doctor, you may believe her. The woman at daycare even asked me if I was a doctor, even though I have been bringing my kids there 8-5 for the past 9 years. 

What does it mean when your daughter is such a good liar that even Mom doesn't know when she is telling the truth or not... and it happens often.  Story telling has just become such a normal part of her life, she thinks nothing of answering the phone and telling her Aunts and Uncles that her name is McKenzie (which it is not) and then telling them they have the wrong number and hanging up.  Right now people giggle when I tell them this story... they say it is so cute.  Well I watch Criminal Minds and Law and Order.  Cute (and annoying) as it is, I can't help but wonder if I don't have a sociopath on my hands. So she's a story teller. So what. She can also be manipulative. Again, it's cute. Now. But at 7 my daughter can flirt with grown men better than I ever could.  She knows when to play dumb (but does it even when it isn't appropriate) and can sweet talk her way with pretty much anything.  I cannot do any of these things. If I could, I would be a lot farther in my career, that's for sure.

So my point is that my daughter has some dangerous gifts.  How do I as a Mom make sure that she uses these gifts for good and not for evil?  My first instinct would be to scorn her and tell her that the lies have to stop. But in her head they are not lies, they are stories. Would my telling her to stop thwart her imagination and suppress who she is?  Any suggestions on this???