Authorities say Aviana Weaver was found safe in Philadelphia on Monday.
Aviana's mother, Angelica Scarlett, says her daughter left their Westampton home on September 11 and said she was going to a friend's house but never returned.
She believed her daughter is the victim of human trafficking.
"We've seen photos of her on human trafficking websites, so we do have proof that she is in danger and something bad has happened to her. This is completely out of character for her," Scarlett told sister station Action News on Sunday night.
Aviana's search gained national attention thanks to social media. Several celebrities have posted messages using the hashtag #bringavianahome.
Aviana is in the process of being reunited with her family.
* More New Jersey news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube