Idk if this will work again, but I was at the end of my time in Driftwood and while she was talking to Trader Bree, I just one-shotted her with my 16 lvl Beast and killed her instantly. The thing is, the fight became townspeople and my party vs the Magisters in the area, not everyone against me.Would love to go back in time to see if this works again, but for now I'll enjoy last minutes of blissful silence in this town. I never thought of trapping her w/barrels etc as described above, will definitely try that immediately next time

Do you visit the sky district very often?

Summon incarnate somewhere away and hide as a barrel. Switch to incarnate and go kill her. Wait until the incarnate dies or summon another one to dispel the killer. Easy silence with no consequences as long as none of your characters join the fight. Turns out it's not that safe among friends.