Ok, here's my off-the-wall idea. I had something specific in mind to ask The Dragon. I was going to ask it to essentially speak with her, and touch her as it touches us.
We can use only words to tell her the value of openness, and the error of her ways. Words are easy to ignore, if you're fixated on a particular perspective. But The Dragon can show her. It can share this feeling and mindset with her in a more direct and fundamentally intimate way than anything we can say. We've certainly tried.
Of course, there is a flipside to this: if The Dragon is with her, it will know her in a way that nearly no one else could. She will be exposed to it utterly, on a deep and fundamental level she may not even have imagined is possible. If this doesn't risk literally traumatizing her, I don't know what would. If the experience does not open her mind, I cannot even imagine the depth of her loathing for it having happened. That may end everything, right then and there.
I'm essentially hoping for the 'divine revelation' angle. There's certainly precedent for people's eyes having been open when touched by a god. Maybe it could even work with her?
Of course, this is all assuming The Dragon would do so in the first place, if we asked it of it.