Very unlikely to the extreme but... Check things like her facebook, twitter account , instagram, website, etc. If she is touring, she would most likely mention it on social media of some kind. Backpage is by far the bet known site across the country so its not impossible she might use it. However, I would expect she would simply post on social media and use a top notch booking service. I cannot imagine she would have any problem getting bookings at any price she wanted.
So yea, scam. Just look at the links for other ads by this poster
FYI, she is in Austin right now.