Kill 10 Blood Elf Reclaimers, and 10 Blood Elf Surveyors before seeking out Magus Rimtori's camp. Once you've found it, look for something that might be important to her that can be used to draw her into a fight.
I thought as much.
We start our crusade against her workers along the southern bluffs on the northern peninsula of Azshara. Kill them with bloody rage--let them know they've betrayed the wrong allies.
Do not concern yourself with her yet--she spends most of her time with her bodyguards searching Azshara. It would be prudent after you've slain her workers to find her personal camp. Scouting out where we can attack her would be wise. Perhaps there is something there we can use to provoke her.