According to IronFist, she was created by the Spirit of the Mountain to guard the Heartstone Forge.
When you first meet her, she hasn't seen a human in years, and is surprised to see you. After you convince her that you wish to defend Dwarfhold from Vath. she sends you on a series of quests that result in her giving you the key to the Uppercity, which breaks. She is the only one who can make you another key to enter through the giant golden doors the Uppercity.
Rock Dweller, I'm glad to see that you're still alive, Humann! But tell me ... what are you doing standing aroud here for? Don't you have work to do?