Sophie Barker was found in a library on the Lower East Side. Photo courtesy of Saida Barker.

Sophie Barker, a mentally disabled 17-year-old, was found safe and sound late Friday afternoon after she disappeared from her father’s Financial District home Thursday morning, her mother, Saida Barker, confirmed. Police found the girl at the Seward Park Library on East Broadway.

“The community showed tremendous support and flooded downtown with flyers and people campaigning in the streets,” Barker told the Trib in a text message. “There were several chats downtown aimed at mobilizing people and thanks to them and the NYPD, we were able to find them.”

Barker called the library security officer “the real breakthrough because he reported the incident after seeing the (All Points Bulletin).” Detectives from the First Precinct “immediately rushed to the scene,” she added, “and subsequently called and FaceTimed Sophie’s stepfather to confirm it was her.” Officers from the Seventh Precinct assisted emergency responders, who led Sophie to an ambulance, she said.

Sophie was last seen at about 11 a.m. Thursday at the corner of William and Wall streets after leaving her father’s house without her cellphone to get a cup of coffee. Her parents feared she might be disoriented because she had forgotten a dose of her medication and was experiencing a “medical emergency,” her mother had told the Trib. Libraries were among her favorite places, a family friend said.