Welcome back Faldorn, the Shadow Druid, who may now join your group in Baldur's Gate II: Enhanced Edition. However, you should remember that she’s a wild one and won't be as peaceful as most druids. On the contrary: she's the wild spark that may start a great fire.
Faldorn can join the party after her original Baldur's Gate II: Shadows of Amn plot. Once you finish the Trademeet quests and become the town's hero, wait for a day or two, and you will be approached by another druid. He will ask you to return to the Druid Grove because something bizarre has happened.
Faldorn has 3 small quests in SoA and 1 small quest in ToB. Furthermore, she may be romanced by males and females of any chaotic alignment with a Strength of 13 or higher and a Constitution of 11 or higher. All these conditions must be met to develop a romantic relationship with Faldorn. However, keep in mind she's not exactly a warm and kind character, and it's reflected in all of her talks.
As with any other WeiDU mod: unzip the archive into your Baldur's Gate 2: Enhanced Edition directory and run Setup-FaldornBG2.exe. Note that this mod requires an up-to-date EE version of the game.