Posts on social media had spread the word about Sheath's disappearance and people reported possible sightings in Taupo and Napier on Thursday.
Police had been informed and were helping but in desperation Gallagher was doing her own investigations as well.
Yesterday she was in Napier hoping to look at video footage taken outside a pizza restaurant.
"I hope none of you ever have to go through this type of hell. Yes, she's run away before, but this time, there's a real risk of her life being in danger," she said.
"All I want is for my daughter to be safe. We are a loving family and she is a very, very important part of this family."
Sheath loved cheerleading and dance and had aspirations of becoming a mechanic as she had a passion for cars.
At the time she went missing Sheath was wearing a red and white striped t-shirt, short black skirt, black "Thrasher" hoody and white Adidas sneakers.
She was picked up by a man driving a dark coloured 1990s Toyota Surf with white paint on the rear left door.
If you have any information on her whereabouts, please contact the police on 105 and quote file number P041388997 or if she is in danger ring 111.