"I was scouted at 14, started modelling at 15 and lived in New York at 16," she says. She has been in runway shows for Marc Jacobs, Anna Sui and Stella McCartney and was the face of advertising campaigns for Gap, Dior and Yves Saint Laurent. She now feels her early career was too much for her.
Rocha says girls are taken out of high school, away from their parents and put into an industry "that treats them as adults, and they do not know how to work with that. They are just thinking, 'How do I please you?"'
Carole White, director of Premier, one of the UK's leading model agencies, says it worries her that several of the big fashion houses, including Prada and Balenciaga, have started using girls aged 13 or 14 to front campaigns or do catwalk work.
She says it's common for girls to be scouted from the age of 13, although they won't work for a couple of years.
"They don't actually do anything [with a model agency] at that age. You tend not to do anything until they're 15.
"They just get used to having their picture taken in the school holidays. And having lots of Polaroids done," says White.
Fashion PR Debra Bourne is co-founder of All Walks on the Catwalk, which campaigns for diversity of age, shape and ethnicity in fashion.
"Hard competition drives them to scout models incredibly young, for fear of losing out," she says. "If models start being used by 15 or 16, this gives the model agency a lead-in period to build the relationship. But I would argue that, emotionally, this is a huge amount to contend with at that age, even though good agencies will argue that they are there to fully protect them."
Victoria's Secret model Behati Prinsloo, 22, has spoken about what it was like to be "discovered" at 15.
"There's no one that helps models figure out what they should do or helps them with their money. It's especially hard for under-age models. You have to figure it out on your own. It's very stressful, it's a lot of travelling, a lot of time away from family, a lot of dealing with stuff you shouldn't be dealing with at that age."
The preference for younger models also influences the aesthetic: the younger she is, the more likely she will be skinny and boyish.
Psychologists at the University of Queensland in Australia and the Centre for Appearance Research at UWE in Bristol are investigating whether we respond as negatively as the fashion industry claims to images of women who don't resemble a slim 16-year-old.
Philippa Diedrichs, the author of a 2011 paper entitled Waif goodbye!, created adverts using a size 8 and a size 12 model and interviewed women about their feelings and likely purchasing decisions after looking at the images.
Younger women, aged 18 to 25, reported feeling despondent about the size 8 picture. They said they would be more likely to buy something if it was advertised by a size 12 model.
This research is ongoing and if it becomes influential, the fashion industry may be forced to challenge the mid-teenage aesthetic as the norm for the "idealised woman".
Keeping it in the family
Anais Gallagher (daughter of Meg Mathews and Noel Gallagher), 11. Though she will only turn 12 at the end of this month, Anais has a portfolio many models aspire to and has featured in adverts for Paul Smith childrenswear.
Kaia Crawford Gerber (daughter of Cindy Crawford and Rande Gerber), 10. Kaia Crawford Gerber is star of the first Young Versace campaign, working on the 2012 line designed by Donatella Versace.
Lottie Moss (Kate Moss's half-sister), 13. Spotted in photographs of Kate's wedding, Lottie Moss had her sister's agents Storm Model Management organising test shoots and has been tipped by fashion bible Vogue.
Betty Lowe (daughter of Pearl Lowe and Danny Goffey), 5. Pearl Lowe's youngest girl embarked on a modelling career like her older sister, Daisy, after they appeared with mum in shots promoting clothing for high-street chain Peacocks.
- Observer