PML-N leader Maryam Nawaz was admitted to Services Hospital Lahore on Wednesday.
According to a document issued by the Services Hospital Lahore Accident & Emergency Services, Maryam was admitted at 10:03pm in VVIP II.
The same night, she met her father, former prime minister Nawaz Sharif, at the hospital, sources within the National Accountability Bureau (NAB) said.
The development had come after a request was sent by the PML-N to the Punjab Home Department asking for special permission to be granted.
"It is already in your knowledge that Mian Muhammad Nawaz Sharif, former three-time prime minister of Pakistan, is unwell and has been shifted to Services Hospital for treatment.
"His daughter Maryam Nawaz Sharif is an undertrial prisoner at Kot Lakhpat Jail Lahore. She has not been able to inquire about the health of her father. It is requested that special permission be granted to (her) to visit her ailing father to inquire about his health," read the letter.
Earlier in the day, a request seeking permission to visit Nawaz had been rejected by an accountability court in Lahore.
Maryam had requested to be granted an hour to meet her father. The PML-N vice president had made the request during court proceedings in the Chaudhry Sugar Mills case.
During the proceedings, the court asked the NAB investigation officer when a reference would be filed in the case, to which he responded that the reference had entered the final stages of preparation and would be filed after approval from the NAB chairman.
Accountability court judge Chaudhry Ameer Mohammad Khan meanwhile extended the judicial remand of Maryam and her cousin, Yousaf Abbas, till October 25.
On Tuesday, doctors at the Lahore Services Hospital had termed Nawaz's condition as 'serious' despite the transfusion of three mega units of platelets within hours after his admission.
According to the medical tests carried out yesterday, the platelet count of the former premier "dropped from 16,000 to a critical level of 2,000" when he was brought to hospital late on Monday night, prompting the medical board members to go for "immediate transfusion of the platelets to save his life", said one of the board members.
NAB had shifted Nawaz to the Services Hospital late on Monday night after his personal physician, Dr Adnan Khan, had raised an alarm about his critical condition in the accountability watchdog's custody.