Ms Baloch's mother, Anwar Azeem, told BBC Urdu that her daughter had shared all her sorrows and secrets with her.
Her father, Muhammad Azeem, said his son should be "shot on sight".
Mrs Azeem said her son lost his mind because of taunts about his sister's frank and often risque posts online.
More than 500 people, almost all of them women, die in Pakistan every year at the hands of relatives who believe shame has been brought on their family.
Ms Baloch became a household name in Pakistan after posting sometimes raunchy photographs, comments and videos on social media sites, on which she had hundreds of thousands of followers.
The 26-year-old was well aware of the opposition she faced in the conservative Muslim country but was unapologetic.
Her brother Waseem has said he drugged and then strangled her to death last Friday "for dishonouring the Baloch name".
(Ms Baloch's brother, Waseem, has confessed to strangling her to death)
In their first interview with international media, Ms Baloch's parents said they had also been drugged on the night of the murder.
"My husband and I fell deeply asleep. We had drunk milk, it had been mixed with sedatives," Mrs Azeem said.
"In the morning, I called Qandeel for breakfast... but she didn't get up."
She found her daughter's body and found that "her whole face was covered in bruises, her tongue was black, her lips was black", and started crying, she said.
"We were mother and daughter, sharing all our sorrows and secrets. She used to tell me: 'Your daughter is working hard, she'll go far,'" she added.
But Ms Baloch's brothers "always had hatred in their hearts", Mrs Azeem said. "Before, they didn't care much. But recently, things got worse, people... poisoned their minds."
'She must have called out'
Mr Azeem said his daughter had been his "best friend", but described his son as "crazed".
"I say he should be shot on sight! He suffocated my little one," he added. "We were drugged, asleep upstairs. She must have called out to us."
Earlier this week, the Punjab provincial government also became a complainant in the murder case, designating it a crime against the state.
The rare move effectively prevented members of Ms Baloch's family from legally forgiving her brother - a common legal loophole that sees many so-called "honour killings" go unpunished.
An anti-honour killings bill to close the loophole nationwide has been bogged down in the Pakistani parliament.
But Prime Minister Nawaz Sharif's daughter said on Wednesday that the ruling party hoped to present it before a joint session of parliament within weeks.