Anecdotal, and not a woman personally, but I’ve had a similar experience from days long gone; ultimately we ended up trying out different toys and the sucking sort of vibrator with lower settings was what got her past the “block”, but it was via masturbation. We’d only move it to our together time after she got comfortable with the sensation and desensitized, as she described it. In our part of the world the main brand name for this kind of toy was “satisfyer”, not sure if that is global though.
After a while it all just clicked and it became something more familiar to me too, with fingers and tongue (though she did still prefer sucking over licking, which for me as a young man back then was new, but very much a priceless enlightenment and a much appreciated skill I later had time to hone more) ultimately joining in and it all becoming something more familiar to my less experienced younger self.
What I’ve learnt since though, is that everyone is so wildly different, that just simply masturbating together, or learning to, if the other party/parties aren’t experienced there, has been key to lasting mutual satisfaction. And people and their needs/wants change over time, that’s also important to keep in mind. And masturbation is the thing that naturally reflects that. Just talk, talk, talk, and then experiment. Try and keep an open mind, and try to be accommodating. Change and new things take time. Try your best not to get frustrated or load too much expectations into the process. And try and understand the other party/parties are the ones having a harder time coming to terms with the fact that they could not meet your initial expectations. They have a lot of pressure due to this, though it’ll ultimately be mutually beneficial.
Also I’ve noted that it’s so easy to fall prey to thinking that you’re the one giving or somehow “improving” their life here, but this is, in fact, your need that needs to get satisfied. You want her to feel things she does not currently. It’s not a bad thing, this is how life is when you share it with someone, but do not think you are being the giving party here. This is your need, which she either chooses to accommodate and figure out together, or not. And you might best start accepting that this experiment might not lead anywhere, and that you might have to change your expectations accordingly.
Just wanted to recommend Luanti (formerly Minetest). Got the whole family playing at the same time eventually, and so I spun a server we can always join individually or together. It’s been really fun, didn’t think I’d like the genre, but it’s pretty zen when it needs to be, yet can have action and exploration too. Especially when trying to watch over and guard the little ones that get a little panicky at times and don’t have the best eye-hand coordination with a keyboard and a touchpad.