Abby was Elder Calhoun’s beloved daughter. There was a ton of stuff he did wrong, but he truly loved and cherished her, and he wanted her to be happy. Abby was deemed unfit for service and basically left alone by everyone as a child, so she never received an education or combat training. People didn’t even really talk to her, which contributed to her language disorder. They’d pat her on the head and send her on her way.
However, Elder Calhoun wanted his daughter to have honor and glory, and after the debacle with Edward Yazzie, he felt that the time was right for her to go out in the world. He purposely chose a large, powerful team led by the distant nephew of his friend, Elder St. James, and placed her there. He genuinely believed that Abby would forget all about Edward if she were to busy herself fighting crime.