Kim Sampson and Samantha Mulcahy died with herpes after the same obstetrician at the East Kent Hospitals University NHS Trust carried out their Caesareans.
Yvette Sampson's daughter had been "fit and healthy" until she gave birth on 3 May 2018, an inquest has heard.
She said the trust had lied about links between the two mothers' deaths.
They were treated by the same surgeon and midwife six weeks apart, neither of whom were tested for herpes, the inquest in Maidstone was told.
Ms Sampson said her daughter had been "in agony" from 3 May when she gave birth to her second child, until she died on 22 May.
She told the inquest she had received "poor treatment" by midwives at the Queen Elizabeth the Queen Mother Hospital (QEQM) in Margate, which she felt also "contributed" to her daughter's death.
Ms Sampson was initially denied a Caesarean and instead told to push for almost three hours, despite repeatedly telling midwives that "something wasn't right" and "clinging to the bed in agony", her mother said.
One midwife refused to transfer her to surgeons, who later admitted that she should have had the operation sooner, she said.
Ms Sampson lost almost four pints of blood after the baby's position meant an artery was torn.
"I could not understand why no-one was listening to Kim or acting on her concerns when she said something wasn't right. The midwives didn't seem to take notice of her pain."
In the following days, Ms Sampson was unable to walk, and her stomach had not deflated, but two midwives who visited their home said they had "no concerns", her mother said.
It was not until 10 May that she was taken to A&E at the QEQM and treated for sepsis.
After four operations to drain fluid from her abdomen, surgeons told the family that "Kim's liver was black and she was unlikely to live".
In July 2018, first-time mother Mrs Mulcahy died from an infection caused by the same virus at the William Harvey Hospital in Ashford.
Ms Sampson said the trust had "lied" to the family about a known link between her daughter's death and Ms Mulcahy's following an investigation.
She said emails from the East Kent trust to Public Health England exposed how they had never tested the surgeon and midwife common to both cases for herpes.
"I am disgusted with the trust and how our family has been treated," she said.
In March, the Mid Kent and Medway Coroner, Catherine Wood, accepted an application from the trust to give anonymity to the surgeon common to both cases.
The inquest continues.