There is possibility that it could never happen.
Communication is key, but in this case the very last thing you want to do is to 'talk about it'.
Her worldview is that it is wrong, and there is no amount of encouragement you can give her to make her feel otherwise.
The best 'hope' (should you wish to pursue this) is simply exploratory.
Do everything on your end only (be it dirty talk, toys, lingerie, etc.) and observe the reaction her body has.
Don't even ask what she thinks. Her words would go through her filter and are likely to not reflect what she is feeling, but instead what she thinks she should feel.
Have her do nothing (since she would likely resent having to do any of it).
When you do X (dirty talk, describing fantasies, toys, etc.) you should be observant to one thing and one thing only.
Does it make her wet?
If so, do more of it and see what adjacencies you can explore.
If it makes her dry, stop and don't revisit it.
If you feel like it isn't making a difference, don't dwell or forse. It isn't the path to success and if lingered on will build resentment.
I am not speaking of posters in this thread, but also realize that most on this forum are complete idiots. They provide generic stereotypical advice (get a large BBC dildo and give it the name of a star she likes, compliment her, etc.).
Seduction and sexual transformation isn't a paint-by-numbers endeavor, it is a tango.
Yes, there are steps, but more important than the 'right step' is that the step is right for your partner at that precise time.