A family is searching for answers after they said their loved one, a 31-year-old mother of three, died one week after testing positive for novel coronavirus.

Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child on April 30. Doctors at UChicago Medicine apparently discharged her even though she tested positive for COVID-19 during childbirth, her family said.

"My sister is not here and it hurts...it's heartbreaking," Clay's sister, Dajah Brown, told "Good Morning America."

In a statement to ABC News, the hospital extended its deepest sympathy to the family but said it could not comment on individual cases due to patient privacy laws.

PHOTO: Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.
Brown Family
Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.

According to family members, Clay had asthma. They said they believe she never should've been sent home with a newborn to fight COVID-19 on her own.

The Centers for Disease Control and Prevention (CDC) says people with moderate to severe asthma could be at greater risk of getting very sick from COVID-19.

PHOTO: Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.
Brown Family
Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.

The American Academy of Allergy, Asthma and Immunology (AAAAI) says published data do not support the CDC's conclusion. One report does suggest that asthma may increase the risk of hospitalization from COVID-19 in 18-49 year olds. This report was based on a small number of patients, the AAAAI notes.

Clay's father, Alan Brown, said his daughter's health got "worse and worse."

PHOTO: Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19. Her newborn daughter appears in this undated family photo.
Brown Family
Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19. Her newborn daughter appears in this undated family photo.

"The doctor that delivered the baby, I want to know if he would've sent his daughter home if she tested positive," he added. "They just dropped the ball."

PHOTO: Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.
Brown Family
Unique Clay, a postal worker from Chicago, Illinois, welcomed her third child April 30. Her family said she died one week later from complications with COVID-19.

Clay is believed to be the first postal worker in Chicago to die of COVID-19. Her colleagues and loved ones recently held a social distancing memorial to honor her.