@spork: Same - I had to have revenge on the FF for the time that I unsuspectingly wandered up north and saw a bunch of elfroot (including royal elfroot) that I immediately ran over to and started grabbing. It was fun - until I suddenly got hit by a fireball, looked up, and noticed the big, angry dragon!
I first saw her flying around fairly early. I think the nearby camp was the first or second one I established. Turned the corner, saw the dragon, thought, "nope."
Went back a few levels later and ventured a little further into the area. Got BBQ'd. Reloaded. Did some other stuff instead.
Finally went back at level 12, had almost completed all the Hinterlands stuff I could, up to that point, and just closed that damn rift by the river, so I was feeling a bit invincible. Decided if I didn't at least try to kill a dragon, I'd never get anywhere with Sera 
Frosty still BBQ'd me twice before we finally killed her.