I had an issue with the Aunty Ethel secondary fight (after you find the secret cave behind the fireplace). I started my characters in stealth after her dialogue and went to attack her to start combat. She registered the attack, and went to move towards the attacker, then stopped and went back to the spot she was. I then used the githyanki to hit her from melee with no response from her. She didn't heal, and I was able to kill her without ever triggering a second fight. I was a custom ranger, my party members being the cleric, the wizard, and the githyanki. I was able to trigger saving the girl, so it didn't break the progression, just allowed me to cheese the fight.
