Charging up to US$7 a time, she works in the poor Antananarivo suburb of 67 Hectares.
"The reason I sought money is because my parents were in financial difficulty. They have difficulties and I can help them. It's me who's paid my school fees since I was 13 years old. I was scared but I made an effort because of my parents' money problems," she told IRIN.
Anecdotal evidence of the increasing numbers of commercial sex workers and growing homelessness in Madagascar's capital, Antananarivo, is providing a snapshot of a country's descent into deeper poverty.
More than three years after Andry Rajoelina deposed President Marc Ravalomanana with the help of the military, the imposition of international sanctions, the cancellation of preferential trade agreements and the withdrawal of international aid are driving up the social indicators of desperation.
Health and social workers are reporting a "worrying" increase in the levels of sex work, particularly among children who use the proceeds to pay for their education, while a local NGO, Ankanifitahiana (Family by God), that provides education for homeless children is reporting increased enrolments.
"I'm always a bit scared, but the room I rent for $5 a day has security," said Nadine. Despite using condoms, she is still concerned about becoming pregnant, as happened to a class colleague of hers.
About half of the $60 a month she gets goes on private school fees; the rest she gives to her parents, who think she works as a waitress. Both her parents lost their $50-per-month pay after the closure of textile factories.
About 150,000 people in the capital working directly and indirectly for textile factories became unemployed after the USA cancelled the country's membership of the African Growth and Opportunity Act (AGOA) on 31 December 2009, following Rajoelina's coup.
AGOA, which effectively supported almost half of Madagascar's $600m textile industry in 2008, gave the country duty-free access to US markets.
Hanitra Rakotoarimanga who heads a basic healthcare centre in Isotry, another of the city's poor neighbourhoods, told IRIN: "In March 2011 the Ministry of Health carried out a survey on HIV prevalence and we recruited 300 sex workers to do the HIV/AIDS test, and from that moment on we noticed that there was at least a 30 percent increase in new cases of sex workers."
Women over 18 are issued with special medical cards which allow for free testing for sexually transmitted diseases, and condoms, but staff at the centre said they were increasingly working with underage girls "off the books".
Miroarisoa Rakotoarivelo, head of the Groupe Développement Madagascar (GDM, an NGO working against the sexual exploitation of minors in Isotry, 67 Hectares and two other downtown neighbourhoods), said a recent survey of 129 sex workers indicated a growing number of children among them.
"It's increased, and the proof I can give you is the January-April 2011 statistics we've got," he told IRIN, adding that almost half of the sex workers sampled were under 18.
GDM targets children of poorer families but has also observed daughters of lower middle class families turning to sex work.
In Isotry, sex workers charge as little as 25 US cents "or just a plate of rice", Rakotoarivelo said, while in the city centre charges can start at $12.
Bernadette Ramanantohasa, 47, has been working as a sex worker in Isotry since becoming a widow in 2002, to supplement her income from hawking vegetables. Her deceased husband used to work as a night watchman at a primary school and earned $7.50 a month for their 11 children, four of whom have died of diarrhoea-related illnesses.
Sex work earns Ramanantohasa about US$15 a month, as she charges between 75 US cents and $3. Four of her teenage daughters have also become sex workers.
"Now we are up against all types of people in this job because so many are looking for money. You even find young girls of 10, 12 and 13. Children are already putting themselves out there," she said.
Voluntary street social worker Christine Rahantamalala has worked with 2,000 sex workers since 1997, but in the last few months, she told IRIN, she has registered 200 new sex workers, a quarter of whom are under 18.
UN special rapporteur on the right to food Olivier de Schutter said on a recent visit to Madagascar that sanctions on the country should be reassessed.
The situation is extremely alarming and should be a wake-up call for the international community because one of the reasons this country is on the brink of a major humanitarian crisis is the sanctions
"The situation is extremely alarming and should be a wake-up call for the international community because one of the reasons this country is on the brink of a major humanitarian crisis is the sanctions that have slowed the country's economic life," De Schutter said, according to an international news service.
An international aid worker, who declined to be identified, told IRIN the rationale for imposing blanket sanctions and punitive economic measures was the expectation that it would lead to the collapse of Rajoelina's administration within a few months of his taking power in 2009, but this did not occur and remained unlikely.
Poverty rates increased 9 percent between 2008 and 2010, according to a UN-supported five-yearly household review.
Alix Heinvelona, founder of the Ankanifitahiana centre which provides education to children of street families, told IRIN enrolments had been gradually increasing since the crisis began three years ago.
"In 2009 we had 225 learners; in 2010 this went up to 255; and now (2011) we have 305 in the school," he told IRIN.
The school, established in 2004, is a collection of wooden huts on a plot of land the size of a tennis court beside open sewers in the Ankorondrano neighbourhood.
"Poverty was bad in 2004," he said, "but now it is very big."
The children are helped by families in the neighbourhood, and the school's food is donated by the UN Food and Agricultural Organization which procures some of the food from a project that supports 1,000 unemployed people with agricultural equipment and seeds.