If you go to the Tangled Shore and go to Petra Venj you can walk up to her and carefully push her around. You can push her anywhere within Spider’s Lair. It you try to push her outside into Thieves Landing she will completely disappear from the game world. Leaving the area and returning, fast traveling and going to orbit and returning will not bring her back. It’s weird she was even there in the first place because I have already completed the Forsaken campaign and the icon for her does not appear on the map. I’m not sure if pushing her to the point where she disappears from the game world will have any effect on other players.