She is for the hedge alt quest, and she spawns near Vhaksiz the Shade. Hail her, kill the Tyrant of Nightmare who spawns by the two guards near the entrance to PoN B and loot a "Heart of the Tyrant". Give that to Kelletia and you get the alt flag.
Partially correct. Turning in the heart is part 1 of the quest. The second part requires a secured wooden case from the Terror Matriarch and two silky cloths from the other spiders in that section of PoN. Your best bet is probably to get all the items, otherwise you have to clear your way to her 3 times ;). A warning - this backflagging quest guide reports that the quest is broken, and I found it so for my BST, who has all EAW flags but hedge/TT.