Yes, it certainly sounds as if you have already, or else you wouldn't know that she's interested on some level. However, explore that level a bit. Has she ever tied you up? Not a bad way to get her in that mode. Once you're helpless, it might inspire some of that domme spirit. Grab a pair of cuffs if ropes aren't your thing and let her feel that surge of sexy power as she binds you and does what she wants to your waiting body.
But just be open, be ready and be supportive.