I posted a little while ago about how badly my new mare behaved for my farrier. He tried a lip twitch, 2 separate shots of Ace/Rompen, then had to go to the vet for a "farrier's cocktail". Definitely talk to your farrier and explain your issues before he comes, so he can be prepared. Maybe a twitch will work. I would recommend you try to start out lower intensity, and work your way up if you need to.
Obviously sedation is not an ideal long-term solution, but if you need to go that route one or more times to get her through her trims, while working with her often in between, that's what you'll need to do.
I hope she surprises you and all the intervention isn't necessary!