Sunam is 3.
The toddler was engaged to her 7-year-old cousin Nieem in June, in a match made by their parents.
Despite the efforts of the government and rights groups, the engagement and marriage of children still persists in this country, especially among poor, uneducated families or in the countryside.
About 16 percent of Afghan children are married under the age of 15, according to recent data from UNICEF. And there is evidence that the poverty of recent years is pushing down the marriage age further in some areas.
The practice can force couples into a miserable union and sometimes expose the girl to violence if she resists.
Sunam's father committed her in marriage as a gift to his sister, Fahima, who does not have a daughter and desperately wants one. Marriage between first cousins is common in Afghanistan because families believe it is better to know their in-laws well. The two families live in the same modest housing compound in Kabul.
"It's a very common problem. I know people in my own family who were engaged this way," said Orzala Ashraf, founder of Humanitarian Assistance for the Women and Children of Afghanistan. "The engagement happens before birth in some cases."
In an unhappy forced marriage, the man can take a woman he loves as a second wife in Islamic and Afghan culture. But the girls are trapped. Some commit suicide - in Kapisa province, just north of Kabul, an 18-year-old girl shot and killed herself because her family would not break off her three-year engagement to a drug addict, Afghanistan's Pajhwok News Agency reported in August.
Others run away, sometimes falling into drugs or prostitution.
"Many girls who want to marry as they wish run away as a threat tactic to their family," Ashraf said. "There is no law that forbids running away, but it is a matter of honor."
The tactic sometimes works. Ashraf helped shelter one 17-year-old girl who ran away from home for a few days, humiliating her parents into letting her marry the man she loved.
The minimum legal age of marriage in Afghanistan is 16 for girls and 18 for boys. Yet child marriages account for 43 percent of all marriages, according to the United Nations. The reasons are often economic: The girl's family gets a "bride price" of double the per capita income for a year or more, according to the World Bank.
In March, the women's ministry and rights group Medica Mondiale started a campaign to encourage marriage registration before a judge, which they hope will cut down on forced and child marriages. Marriage registration is already mandated but rarely practiced.
The families of Sunam and Nieem are convinced that if the two grow up together knowing they will be married, they will be happy to wed in the future. The plan is for them to marry when Sunam is 14 or 15.
Nieem's mother, Fahima, said if the children grow up to dislike each other, the families will break off the arrangement. "It's their whole lives. If they don't like each other they will have problems their whole lives," she said.
But according to the children's aunt, Najiba, the match is unbreakable.
"We are Pashtun people. If we engage them, there is no way to separate them. They will marry," Najiba said. "In our tribe, it is like this. When they get engaged, they cannot divorce."
Many engaged couples do not meet until after they are married. In some cases, two pregnant women - either sisters or good friends
agree to make a match if one has a boy and the other a girl.
Girls from fatherless families - there are many in war-torn Afghanistan - often are forced into the worst engagements. Jamila Zafar, a social worker for rights group Women for Afghan Women, says it took 2½ months of negotiations to free 14-year-old Mudira in Paghman province outside Kabul from her engagement.
Mudira had lost her father, and her uncle forced the girl into an engagement with his son, a handicapped amputee. When the son died, the uncle engaged her for a second time to another handicapped son.
When Zafar's colleagues talked with the uncle and his family, the relatives threatened to kill them and went to Mudira's house to beat her stepfather. Only under pressure from Paghman police and officials was the engagement called off.
It is nearly impossible to break engagements "because you're considered the other family's property. You're theirs now. You've been given away," said Manizha Naderi, director of Women for Afghan Women. "It's obviously barbaric. It's going to take generations to change this custom."
One 22-year-old woman from Kabul has tried to break off her engagement for eight years. Her 36-year-old fiance - whom she describes as uneducated, conservative and cruel, "like a Taliban"
has threatened to kill her if she refuses him. His father has also beaten her.
"I have told my mother for eight years that I don't accept this man," the engaged woman said, asking that her name be withheld for fear his family would attack her. "My mother said, 'What can I do? You don't have any brothers, you don't have a father."'
Her father died in a car accident when she was 6 months old, so a close friend of her father took it upon himself to find her an appropriate husband - his son.
She is educated and works for a prominent international organization. Her fiance is a tailor with a high school diploma.
"I'm young. I want to go to school," she said, at a coffee shop in a Kabul shopping mall. Her voice was full of desperation and resignation.
"This is Afghanistan. That's why I don't like Afghanistan. I will leave Afghanistan."