A 13-YEAR-old girl who admitted her part in kidnapping a toddler had been sexually exploited online, a court heard.

The younger of two girls who snatched a two-year-old from a Primark store was groomed by an unknown man who messaged her tablet computer using the ooVoo app, Newcastle Crown Court heard.

The app was deleted, meaning a police investigation into the man's identity was hampered, but screenshots taken of a conversation indicated it was sexualised, Sarah Barlow, prosecuting, said.

"He was asking for photos of her," she said.

"It appears she sent a photo of herself and (the older defendant) to him."

There was no evidence to suggest this man was in any way involved in the girls' abduction plans, the court heard.

Julie Clemitson, defending the younger girl, said she was vulnerable, and had been sexually exploited.

Andrew Walker, defending the older girl, said his client displayed signs of being on the autistic spectrum and had a lack of social understanding.

She displayed a "preoccupation" with babies, he said.

The barristers opposed a submission from the media to name the defendants, saying that due to the nature of the case, they risked reprisals from the public.

The judge agreed, saying that being identified would not help their rehabilitation process.