KABUL, Afghanistan — When she refused to prostitute herself or have sex with the man she was forced to marry when she was about 13, officials said, Sahar Gul’s in-laws tortured her and threw her into a dirty, windowless cellar for months until the police discovered her lying in hay and animal dung.


In July, an appeals court upheld prison sentences of 10 years each for three of her in-laws, a decision heralded as a legal triumph underscoring the advances for women’s rights in the past decade. She is recovering from her wounds, physical and emotional, in a women’s shelter in Kabul.


But to many rights advocates, Sahar Gul’s case, which drew attention from President Hamid Karzai and the international news media, is the exception that proves the rule: a small victory that masks a still-depressing picture of widespread instances of abuse of women that never come to light.


Further, advocacy groups fear that even the tentative progress that has been achieved in protecting some women could be undone if the West’s focus on Afghanistan now begins to shift away as NATO troops withdraw and the international money pumped into the economy diminishes.


“If you take away that funding and pressure, it is not sustainable,” said Heather Barr, Afghanistan researcher for Human Rights Watch.


As more details of Sahar Gul’s case have come to light — including the fact that the abuse continued even as, time and again, neighbors, police officers and her family members voiced suspicions that something was wrong — it has only reinforced how vulnerable women and girls still are in Afghanistan, particularly in rural areas where under-age marriages are common and forced ones are typical.


Sahar Gul, who is now about 14, grew up in Badakhshan, a poor, mountainous province in the north. As a young child she was shuffled around after her father died, ending up with her stepbrother, Mohammad, when she was about 9. She helped with the hard work — tending cows, sheep and an orchard of walnut and apricot trees, and making dung bricks for the fire — but her stepbrother’s wife resented her presence. The woman pressured Mohammad to give Sahar Gul up for marriage after he was contacted by a man, about 30, named Ghulam Sakhi — even though she had not yet reached the legal marriage age of 16, or 15 with a father’s consent.


In effect, Ghulam Sakhi bought her: he paid at least $5,000, according to government officials and prosecutors, an illegal exchange. He drove off with Sahar Gul to his parents’ home in Baghlan, another northern province hundreds of miles away.


Ghulam Sakhi’s first wife had fled after he and his mother beat her for not bearing children, according to Rahima Zarifi, the chairwoman of Baghlan’s women’s affairs department, and the mullah in the mosque in the town in Baghlan. In his search for a new wife, there may have been a reason Ghulam Sakhi’s family looked so far afield: they intended to force her into prostitution, according to Ms. Zarifi, who followed the case closely, and officials at the Ministry of Women’s Affairs in Kabul.


In Baghlan, the girl was immediately put to work cooking and cleaning, but she was able to resist consummating the marriage for weeks.


She ran away to the house of a neighbor, who alerted both the police and her husband’s family. Ghulam Sakhi’s neighbors and the police forced him to sign a letter promising not to mistreat Sahar Gul, though they let him take her back.


The warning had little effect. One day, when she complained of a headache, her mother-in-law, Siyamoi, tricked her into taking a sedative that she thought was medicine, said Mushtari Daqiq, a lawyer for the aid group Women for Afghan Women and also Sahar Gul’s lawyer.


“When she woke up in the morning, she realized she had been used by her husband,” Ms. Daqiq said.


A neighbor named Ehsanullah said that one evening last summer, as his family ate dinner, they heard screaming coming from the house. The following morning his mother called at the house. He recounted what she saw: “Sahar Gul had lost a lot of weight, her hands were covered with bruises and wounds, one of her hands was broken, but her mother-in-law was forcing her to do the laundry.” He added, “She kept her head down the whole time my mother was there.”


After a group of elders confronted Ghulam Sakhi, the screaming stopped.