Branwen Rescued, also known as Freeing Branwen is a companion quest that appears in the journal instead of the quests tab.
Between two of the carnival shops, a dwarf named Zeke can be found - he screams for attention, anyway. He will tell you about the statue behind him if asked.
Walkthrough[]
Branwen in stone form
The statue behind Zeke is in fact a human cleric named Branwen, who was cursed by the mage Tranzig. She was turned to stone, and can be revived with a Stone to Flesh scroll.
Zeke offers to sell such a scroll for 500 
, but it can be pickpocketed from him instead, or Zeke can even be killed, although that results in reputation loss. He can also be charmed and a scroll can be used from his quick slot. These scrolls can also simply be bought at most temples for much less gold, the nearest being the Temple of Helm in Nashkel.
Once a scroll of Stone to Flesh has been acquired, it should be placed in a quick-item slot of the inventory and cast on the statue. Branwen will be brought back to life injured, and the scroll will vanish. When she's spoken to, she will offer to join your party as a reward.