As the nation's most vocal and well-known activist, the 32-year-old mother of three is helping to shatter perceptions of women in this conservative society, while emboldening a new generation of Yemenis to demand an end to President Ali Abdullah Saleh's three-decade-long grip on this country.
"We are in need of heroes," said Abdul-Ghani Al-Iryani, a Yemeni political analyst. "She manages to do what most men cannot do in a society that is highly prejudiced against women."
Since Egyptian President Hosni Mubarak stepped down after nearly 30 years in power Friday, thousands of reenergized Yemenis, from students to laborers, lawyers to human rights activists, have taken to the streets of Sanaa and other cities to speak out against Yemen's corruption, high unemployment and lack of basic freedoms. The anti-government protests, while still small compared with those that transformed Egypt and Tunisia, are getting louder and more confident.
On Sunday, the protesters marched for the first time to the presidential palace. And Monday, they clashed with pro-government demonstrators outside Sanaa University.
"After Egypt, all the dictators in this region will fall, and the first one will be Ali Abdullah Saleh," Karman said. "Egypt has given us a model, because Mubarak was the strongest dictator in the region. We now believe we can bring revolution here."
While women have actively participated in the protests across the Arab world, the symbols of defiance have mostly been men. Tunisia had Mohamed Bouazizi, the fruit seller whose self-immolation triggered the popular uprising that ended the rule of Zine el-Abidine Ben Ali. Egypt had Wael Ghonim, the Google executive who energized the pro-democracy demonstrations that ultimately pressured Mubarak to resign.
Few expected a woman to lead the charge in Yemen, where the vast majority of protesters have been men. Most women here are not free to marry whom they want; many are married off as children. In court, their testimonies are worth half those of men. When women are murdered, their families are compensated at half the amount they would receive for male victims. They are also treated unequally in matters of inheritance. Violence against women is rife, human rights activists say.
"Tawakkol is one of the bravest people in this country," said Khaled al-Anesi, a lawyer and pro-democracy activist. "It is not easy for a woman to fight and go to the streets demanding change in a country like Yemen."
Two weeks ago, Karman's brother Tareq approached her. A well-known poet, he personally knew Saleh, and he was carrying a message from him.
" 'You have to control your sister. Anyone who doesn't obey me must be killed,' he told my brother," said Karman. "This is the one threat I take seriously."
In interviews, senior Yemeni officials and members of the ruling party said they were unaware of the allegations. They said Saleh would not make such a threat. But they also made clear that they considered Karman a troublemaker.
"She doesn't respect the president, the government or the law," said Sultan al-Barakani, a senior official in the ruling party. "She says bad things about the president."
It was not the first time Karman had felt in danger. She has received numerous text messages warning her to stop her activism or be killed. At a recent rally, a pro-government mob attacked her with knives and sticks, but her supporters protected her.
On the night of Jan. 23, Yemeni security officers arrested Karman and threw her in prison on charges of illegally organizing demonstrations and inciting people against the president. That triggered protests on the streets and more calls for regime change. The government freed Karman after 38 hours, saying that her family promised to restrain her.
Karman sees her release as a sign that Saleh was worried that the revolts spreading across the Arab world could affect his rule.
Karman was born in the southern city of Taiz into a large upper-middle-class family. Her father served as legal affairs minister after northern and southern Yemen unified in 1990. After civil war broke out four years later, he quit the government but remained active in the opposition.
At Sanaa University, where she studied psychology, Karman became politically active. She joined Islah, the nation's most influential Islamist opposition party. First, she published articles on the Internet denouncing Yemen's rampant graft. Then she lobbied for press freedoms in Yemen by staging sit-ins outside the Ministry of Social Affairs. She managed to secure the release of several journalists jailed for their writings.
Even Karman's attire is imbued with a sense of defiance. In a society where the vast majority of women are dressed head to toe in black abayas, she favors a pink, floral-patterned head scarf.
The day after Ben Ali fled Tunisia, Karman organized the first student demonstrations at Sanaa University, calling for Saleh to step down. She used Facebook and cellphone text messages to urge protesters to come out. And as uprisings grew in Tunisia and then in Egypt, so did the demonstrations in Yemen, culminating in some of the largest gatherings the nation has seen in recent times.
But she's also aware of the obstacles to removing Saleh. The political opposition, including her party, wants reforms rather than regime change. Civil society is weak. Yemen's middle class is small, while illiteracy rates are high. The Internet is not widely used, making it hard to stimulate change.
Still, there have been victories. Among a number of promised reforms, Saleh has pledged not to run for office again when his term expires in 2013. Nor will he anoint his son to replace him, he said.
That has only encouraged Karman, for she doesn't believe Saleh will keep his promises.
She predicts the momentum on Yemen's streets will grow.
"I am sure all the people will rise up in revolt under the slogan 'Go out,' " she said. "This is a historic opportunity that must be exploited."