Before you TOFTT, if you haven't already I would google her number, google her pics, google her email if she has one, try to discover her social media and last but not least ask if she does facetime chat? Even if she asks for $30- $50 for a video chat. While none of this would insure her performance, if you're able to flirt with her through a video chat you can possibly learn a bit more about her personality, ask shy she doesn't have reviews, confirm if the pics are real or fake and so on...