Meriam Ibrahim's chains were removed on doctor's orders after she gave birth to a daughter in jail in Khartoum's twin city of Omdurman.
She was also moved from the prison cell she shared with other inmates to a prison clinic with a bed and air conditioning, her lawyer told AFP.
The case of the 27-year-old mother of two sparked an international outcry when a judge sentenced her to hang last month after she was found guilty of apostasy and adultery for marrying a Christian.
Born to a Muslim father, she was convicted under Islamic sharia law that has been in force in Sudan since 1983 and outlaws conversions on pain of death.
She gave birth just 12 days after the verdict. It had been thought she was still shackled throughout the delivery and beyond, according to the rules which stipulate the treatment of death row inmates in Sudan.
But Mohanad Mustafa, one of Ms Ibrahim's lawyers, told AFP yesterday that jailers removed the chains after she gave birth to her daughter.
'This is on order by the doctor,' he said, adding that he didn't think the shackles would be put back on again.
'After she gave birth the conditions got better,' said Mr Mustafa. 'She has air conditioning. She has a good bed,' he said after he and Ms Ibrahim's Catholic husband, Daniel Wani, visited her.
'She's fine. Usually her husband brings the food, and he gives her money' to buy any other items she needs.
The couple's 20-month-old son is also in prison with Ms Ibrahim and her daughter. Mr Mustafa said that despite the relative improvement in the conditions they are being kept in, 'a prison is a prison.'
Western governments and human rights groups have pressured the Sudanese to release Ms Ibrahim.
Last week, European Union leaders called for revocation of the 'inhumane verdict,' while U.S. Secretary of State John Kerry urged Khartoum to repeal its laws banning Muslims from converting.
Prime Minister David Cameron said the way she has been treated 'is barbaric and has no place in today's world.'
Mr Mustafa and four other human rights lawyers handling her case for free have appealed the verdict.
'We're still waiting,' and there is no word on when the higher court's decision may come, Mr Mustafa said.
A church source was optimistic Ms Ibrahim would be freed because of international pressure on Sudan. 'I am hopeful that she will be released,' said the source, who asked for anonymity.
But Muslim extremist groups have been also lobbying the Islamist government over the case, prominent newspaper editor Khalid Tigani has said.
Ms Ibrahim, born in eastern Sudan's Gedaref state on November 3, 1987, is the daughter of a Sudanese Muslim father and an Ethiopian Orthodox Christian mother, according to a statement from the Roman Catholic Archdiocese of Khartoum.
SUDANESE GOVERNMENT BOMBS HOSPITAL RUN BY AID GROUP
The aid group Doctors Without Borders says an aerial bombing run over a Sudanese village hit one of its medical facilities, partially destroying a hospital.
The group said Tuesday the bombing run in the southern Sudanese region of South Kordofana occurred Monday. The group said five people from the village and one Doctors Without Borders staffer were wounded.
The group's head of mission, Brian Moller, said the group is shocked that its medical facility was hit, especially since it is clearly identified with a flag and a cross on the roof. He said Khartoum's government knows where the hospital is.
Residents in the region say the Khartoum government has increased bombing runs in recent weeks. Sudan's military is fighting soldiers more ideologically aligned with South Sudan.
Her father abandoned the family when she was five, and she was raised according to her mother's faith, it says.
'She has never been a Muslim in her life,' said the statement signed by Father Mussa Timothy Kacho, episcopal vicar for Khartoum. Miss Ibrahim joined the Catholic church shortly before she married the Mr Wani in December 2011, the vicar said.
Mr Wani was born in Khartoum but is now a U.S. citizen, the U.S. embassy confirmed to AFP on Tuesday.
The case against Ishag dates from 2013 when 'a group of men who claim to be Meriam's relatives' filed an initial legal action, the vicar's statement said.
In fact, she had never seen those men before, the statement added, in comments confirmed by Mr Mustafa.
Ms Ibrahim, who is a trained doctor, and her husband own a barber shop, a mini-mart and an agricultural project in Gedaref, the vicar said.
Mr Mustafa did not know if there is a link between the businesses and the case against Ms Ibrahim, but he told AFP: 'Surely there is something behind this'.
The case is the latest problem facing Sudan, an impoverished nation battling rebellions in its west and south, while more than six million people need humanitarian aid.
This may not be an effective strategy for inspiring humanitarian aid.