Their only income is her father's daily wage of up to 200 rupees (less than NZD$3.90) for labouring on construction sites. Their most precious possessions include a study table and a second-hand computer.
It is not a great atmosphere for studying, she admitted. "There are a lot of dreams ... All of them cannot be fulfilled."
But having no television and little else at home has advantages, she said. "There is nothing to do but study."
Sushma begins her studies next week at Lucknow's B. R. Ambedkar Central University, though her father is already ferrying her to and from campus each day on his bicycle so she can meet with teachers before classes begin.
Her first choice was to become a doctor, but she cannot take the test to qualify for medical school until she is 18.
"So I opted for the MSc and then I will do a doctorate," she said.
Sushma - a skinny, poised girl with shoulder-length hair - is not the first high-achiever in her family. Her older brother graduated from high school at 9, and in 2007 became one of India's youngest computer science graduates at 14.
In another family, Sushma might not have been able to follow him into higher education. Millions of Indian children are still not enrolled in grade school, and many of them are girls whose parents choose to hold them back in favour of advancing their sons. Some from conservative village cultures are expected only to get married, for which their families will go into debt to pay exorbitant dowry payments, even though they are illegal.
For Sushma, her father sold his only pieces of land - 930 square metres in a village in Uttar Pradesh - for the cut-rate price of 25,000 rupees (about NZD$490) to cover some of her school fees.
"There was opposition from my family and friends, but I did not have any option," said her father, Tej Bahadur Verma.
The rest of Sushma's school fees will come from a charity that traditionally works in improving rural sewage systems, which gave her a grant of 800,000 rupees (about NZD$15,600).
"The girl is an inspiration for students from elite backgrounds" who are born with everything, said Dr. Bindeshwar Pathak of Sulabh International, who decided to help after seeing a local television program on Sushma. She is also receiving financial aid from well-wishing civilians and other charities.
- AP