The out of home ads, which were created in-house by the brand, showed a woman sitting on a large chair with one leg slightly raised, and another showed the model resting on the side of a sofa with one leg resting on the arm.
The Advertising Standards Authority received three complaints about the ads saying that the model’s facial expression and poses sexualised someone who appears to be a child.
Another added that with the name Nobody’s Child, the ads implied the image was of a vulnerable child.
Nobody’s Child agreed that the images were open to interpretation but said the model was not being sexualised and was not seen as a child. It added that the model was 21 years old.
With regards to the name of the brand, the company said that it was "intended to reflect the feeling their target audience experienced, that they were no longer children and were now their own person".
However the ASA said that the model appearing next to a brand named Nobody’s Child would be seen as a child.
It added: "In that context, we considered that the model’s poses implied vulnerability and sexual precocity.
"We therefore concluded the ads portrayed a model who appeared to be a child in a way that was sexually suggestive and could be perceived as being vulnerable."
The ASA said that the ads were "irresponsible and likely to cause serious or widespread offence" so has banned them from appearing again.