This is the final boss for the left wing. A few preparations need to be done before you can take down this boss, 1)Ensure the torch is on your hotbar. This quest item is required to remove the webbing she throws out periodically. 2)Make sure at least 2 members of your party are able to do some constant AoE around her.
The reason is as follows: This boss generally begins each battle by throwing player back, and attaching a webbing on them which will NOT break unless you activate the torch. The tank should be the first one to remove the webbing as the first player doing so will usually draw aggro from the boss as well. From this point onwards, she will continuously have little spiders make their way towards her. If any spiders successfully reach her, they will buff up her damage by 5% per spider. This is where the AoE portion comes into play. At all times, ensure that there is some AoE going on around her to kill the small spiders. They die very easily, but come in large numbers and from multiple directions. Now, she will periodically throw out webbing, which will again deal knockback and root, so it is imperative that the main tank have his back up against a wall or something to try and limit the KB as much as possible. Keep this up, and the boss will drop easily (barring any weird bugs that might cause her to reset or jump to 500% more damage, or people getting stuck because of getting knocked in weird places).