You might consider two sessions. The first one is get acquainted with more vanilla stuff. The second one is balls to the wall.
You might be able to glean something from them, and you can contact some of the reviewers by PM if you have VIP, and then ask them questions about what to expect.
Otherwise, it's going to be an adventure, and I hope a good one.
While it's nice to know a bit of what to expect in advance, just enjoy the ride. If her reviews are decent I'm sure you will be able to sit and discuss limits and what toys are available for use at the beginning of the session.
Find subs like Angie and read her reviews and get an idea what others have done during a session.
. . .trust that she'll have her gear with her.
I echo the advice re: reviews.
Unless you've already emailed her about this, you can also shoot an email and be like, "Hey, I hope I'm not overstepping any boundaries but I was hoping that we could discuss hard/soft limits and some gear requests I have before we meet. "
It signals to her that you're not looking to have a graphic conversation with her and you are conscious of boundaries.
If you've already sent out the email and she's stalled the conversation, then I'd say to trust her process.
Some advertise sessions they should not as a means of marketing to gain $, but fake it until you make it is not right. You want someone who is open to discussing everything prior to play. I am fully equipped, and most have a simple fantasy started kit that may not be what your looking for, so ask. I send photos to my potential clients who inquire about my dildo sizes, toys, etc. They should be able to know upfront what to expect.
I myself like to have an idea of what the person wants coming into the session before meeting. Gives me time to think about where I want to take session. I do give the first 10 min to discussion about wants/taboos in session so maybe she is doing this. Hope u have a good time! Reviews may not always help because for myself I have been doing BDSM for 7 years and never had a review for that particular genre of my work. Some people do not want reviews or advertisements or any internet presence for protection from the real / corporate world. For some of us this is a secret realm 
She TOLD you she wouldn't discuss details, or is that just what her site says?
I know that I am *much* more willing to discuss details once screening is done and a session is pre-booked.
If she won't discuss details, maybe you should just tell her what you hope for, making it clear that you don't expect her to DISCUSS anything if she doesn't want to, just letting her know what YOU like. Hopefully, if she is not on the same page, she will back out of the booking. That is what I have done when it's clear a potential client will not be happy with what I provide. I just tell them I don't think we are a good match, and if I know someone who does offer what they want, I will make a recommendation.
I think most reputable providers would rather not see someone who they know will not be happy with the experience. No one wants bad reviews, and even if they are gracious about it, spending an hour or two with a client who you can't please is really not fun. At least not for me! I like to be around happy, appreciative guys whose worlds I can solidly rock!
