Kill the Leader of Gallows Rock

Speaking to Annekke Crag-Jumper at Goldenrock Mine, she tells you she use to be an adventurer (but didn't take an arrow to the knee) and was doing a little scouting eariler. She spoted a bandit group heading towards Gallows Rock and asks you to take care of the problem.

Once you have dispatched of the bandit leader, you can have her become a follower.