COVID in pregnancy can be extremely serious, and one Florida family is grieving the loss of a young, healthy new mom who died from the virus just days after giving birth to her daughter via emergency c-section.

Kristen McMullen, who was only 30 years old, was hospitalized with COVID-19 on July 21. She was diagnosed with pneumonia and sent home after a few days, but returned to the hospital again on July 26. Her daughter, Summer Reign, was delivered by emergency c-section on July 27. Tragically, McMullen was placed on a ventilator on August 6—she died later that same day.

"That first week, honestly Kristen's main concern was Summer and just making sure that she was OK," said her aunt, Melissa Syverson, per NBC News. Summer is healthy and currently in the care of her grieving family. McMullen's uncle, James, says the severity of Kristen's illness came as a shock to the family because she was perfectly healthy.

"She never got sick, and we assumed like many people that this would just go away just as quickly as it came," he said. "Because with a lot of younger people — she was only 30 years old — that she would breeze through it and be back taking charge of life."

Though her family declines to say if McMullen was vaccinated against the virus, they told NBC News that they hope people take the virus seriously.

"We personally feel that whether a pregnant woman is or isn't (vaccinated), or whether they wear a mask or don't wear a mask, we feel like they're at a huge risk potentially for it to be deadly for them or their baby," Melissa Syverson said.

According to a fundraiser organized by her family, McMullen and her husband battled infertility before conceiving baby Summer.

"Kristen dreamed of being a mom and after several years of fighting an uphill battle, her and her husband Keith, received the good news that they were expecting," the site says.

Earlier this week, the Centers for Disease Control and Prevention doubled down on urging pregnant people to get the COVID-19 vaccine. The delta variant is causing case numbers to skyrocket across the U.S., and the CDC reports only 23% of pregnant people have received at least one dose of the vaccine.

Contracting COVID-19 while pregnant carries significant risks for both pregnant people and infants, including preterm birth. Even those who have been recently pregnant are at increased risk of severe illness from COVID-19.

Kristen McMullen's family now joins the millions of families grieving the painful and tragic losses of their loved ones.

"Yesterday, Kristen took her last breath," the family wrote on the fundraiser's website. "A 30-year-old bright, beautiful, vivacious girl with the world ahead of her. She leaves behind her husband and best friend Keith and a beautiful one-week-old baby girl, Summer Reign. The loss of Kristen; wife, mother, granddaughter, niece, aunt, friend, and so much more... is devastating to our family and we can't imagine life without her."

If you'd like to donate to the GoFundMe set up by the family of Kristen McMullen, you can donate here.