Nicky Thompson, 21, and her partner Beau Degeorge were accused of waiting days to get treatment for the baby, and have both been found guilty of cruelty.
The woman had noticed the swelling on her six-month-old daughter's head but waited two days before taking her to hospital - even going shopping for new curtains in the interim.
The Mail reports that when medics eventually saw the baby, they discovered severe and 'boggy' swelling on the right side of her head, which was revealed to be from a skull fracture, while swelling on the left side was the result of a complex fracture.
Snaresbrook Crown Court heard that 30-year-old Degeorge originally told police he had lied to Thompson about taking the baby to a walk-in centre in order to avoid 'an argument'. It was said he could not be bothered to take her to hospital when the swelling was first noted on September 30, 2011 because he would have had to take two buses to get there.
It was not until October 2, when the baby's eyes were vacant and she had not been her usual self that Degeorge finally took her to Homerton Hospital.
Prosecutor Emma Smith said the pair had 'neglected their child'.
"It would appear that despite seeing the swelling, they thought the baby did not need medical attention," she said. "Thompson says that on seeing the swelling she thought the baby did need medical attention but rather than taking her herself, she told Degeorge to go - but he didn't.
The child wasn't getting any better, but rather than taking her to the doctor, Thompson chose to go shopping for curtains with her mother."
Judge Judith Hughes QC said she needed to consider if Thompson could do a form of community service that would help her with parenting skills.
"It really comes down to this - why didn't both parents take her to the hospital on that Friday when they say they first noticed the swelling?" she asked. "Fortunately there was no obvious brain damage sustained by this child."
The couple were both found guilty of a single charge of cruelty to a person under the age of 16 and will return to court for sentencing in January.
Degeorge was remanded in custody, while Thompson was released on bail.