"She would only stay in [the pack] for about a minute, and then she'd want to be on the ground walking behind Atlas, so I figured I'd give her a try," Christie said. "We were in a nice, quiet park without a lot of people around, so he just charged ahead and walked down the trail and she just started following him."

Atlas might have been taking the lead, but he frequently checked up on Nell.

"He would turn around and make sure she was OK … and come back and check on her," Christie said. "She would just follow him to the ends of the earth, and she just seemed super confident as long as he was there. If she couldn't see him, she got nervous."

Whenever Christie tried to pick Nell up, Nell would wriggle out of her arms.

"She didn't want to be with me — she wanted to be with him," Christie said. "And then she was really confident, and she really enjoyed going out too."