1. Looks for reviews of the provider on this site/oh2/etc
2. If provider asks for money upfront, likely a scam
3. Chat with provider and see if the story matches up
4. This provider @400/hr sure seems rocking. Don't meet her at your home. Find a hotel or something at
https://www.dayuse.com
5. Take one for the team and post a review of her if you luck out
6. Check if the pictures are stolen.. Reverse image search the provider. Many times, pictures don't match the provider - Either pics are too old, are of diff provider, stolen from internet etc.
As always, if your spidey sense tingles at any time, run. An hour of fun is not worth a lifetime of troubles.