Some hours later, Cowan found the girl sitting with her children in a bedroom, watching television.
"She had turned back up again, I don't know how long she had been there," she said.
"I questioned her, but she wouldn't really give me any answers," Cowan said.
"Then I turned on my Facebook and I saw posts about the missing girl and her photo."
Cowan posted an immediate message on a local residents' group page, telling everyone the girl was okay and her parents could call her.
"That's when my phone started ringing," she said. "By now, the girl was asleep so I went and woke her up and said 'Bub, everyone's looking for you'.
"She was very quiet, she had nothing to say really."
Cowan then saw a group of searchers on the street outside.
"I ran out and told them 'she's here, she's safe'."
Cowan said she now felt foolish for not having acted sooner, leaving a family and community to worry for so long.
"My neighbour had said she knew the girl's parents, I thought it was okay but obviously it wasn't. I should have rung the police, yes. But you live and you learn."