I'd say meet with her, ask questions, and see what you think. I wouldn't make a good impression over the phone probably either, because I don't do phone that well. So I'd give her the benefit of the doubt there.

The line about private pay and confidentiality is fairly standard, actually. Confidentiality does have limits, such as if you want your insurance company to be billed then they will require some information. She's just saying that you have the option with her of paying privately so that she isn't required to share any information for billing. I'd want to know if she accepts insurance if you do want to use your insurance. Some Ts only accept private payment, and some only work with insurance, or medicaid, or whatever. You just have to ask them.