Braylynn Lawhon and her grandfather, Sean Patterson. (Courtesy of Ally Parker)

Braylynn Lawhon's nickname was Princess Bel.

Nurses in Florida recently dressed the terminally ill 5-year-old girl in a canary yellow ball gown, “hoping she'll wake up and lose her mind over how she turned into a princess overnight,” her mother wrote Friday on Facebook.

“What she doesn't know, though, is that she has ALWAYS been a princess,” she wrote.

“#Fightlikeagirl,” she added.

Three days later, Braylynn died.

The child had been diagnosed just days before her 5th birthday with diffuse intrinsic pontine glioma, a rare type of brain tumor. Doctors said then, in early December, that she probably would not live much longer.

In Braylynn's final days, her mother shared a heartbreaking photo: It showed the young girl, connected to a mess of tubes and wires, lying motionless in a Pensacola hospital bed, her grandfather sobbing inconsolably at her bedside.

“Princess Braylynn is still with us,” the caption read. “Her pulse is barely there and we can not feel it, but we can hear it with a stethoscope. Nurses say she may not make it through the next hour, but miracles can still happen.”

The wrenching photo went viral as countless strangers shared in the family's pain.

All the while, Braylynn's aggressive cancer continued to attack her small body.

On Monday, Braylynn's Battalion, a Facebook group created to keep people updated on the child's condition, posted an announcement: “Our sweet Braylynn, our warrior princess, earned her sparkly pink angel wings this evening.”

“She was a princess with the strength of a warrior and she will NEVER be forgotten,” Braylynn's Battalion said.

“We need this cruel disease called DIPG to stop taking our children away from us!”

According to Boston Children's Hospital, diffuse intrinsic pontine gliomas (DIPGs) are “highly aggressive and difficult to treat brain tumors” that grow near the brain stem, which controls breathing, heart rate and blood pressure.

About 300 children, most often between ages 5 and 9, are diagnosed with DIPGs each year, the hospital said. The prognosis “remains very poor.”

“We were told that she had between 24 and 48 hours,” Braylynn's mother, Ally Parker, recently told TODAY Parents. “The doctor who gave us that time frame came in later and told us she lifted the frame because she believed Braylynn could be fighting for several more weeks, even years.”

Good morning, sweet girl.You're still fighting, so I'm going to keep fighting with you. Mommy's still here, and I'll be here every second. 💛💛💛💛💛#BraylynnsBattalion #Fightlikeagirl #DIPG

Posted by Ally Parker on Saturday, January 13, 2018

By early January, the young girl was deteriorating rapidly. Her mother posted a photo Jan. 5, asking for prayers.

“We're in the ER,” she wrote on Facebook. “Braylynn has been sounding very congested today. We've had a CT done and they said they think there may be a small bleed in the tumor, but they don't know for sure. They're putting her on a few new meds to decrease swelling just in case, and starting her on a breathing tube...”

Then: “Braylynn has just been given 24-48 hours. The staff here says there is nothing they can do...”

Then: “The doctor who originally gave us the 24-48 hour timeline just came back. She has realized that Braylynn is NOT like most kids. . . . We no longer have the 48 hour maximum timeline, or even one at all really. She is still winning, she can still beat this.”

Then: “Went downstairs to Starbucks . . . came back . . . doctor told us my little baby is basically braindead.”

It was an emotional roller coaster that led up to the moment Parker revealed her family's heartache, in the Jan. 7 hospital photo that went viral.

Parker never thought the image would make such an impact, she told TODAY Parents.

“I had no intention of that picture getting as far as it did,” she said. “I had taken it just to capture a memory — to remind myself that this was real and it was happening.”

Parker said her father, the girl's grandfather, was struggling the most.

“He hopes that one day, the two of them will be sitting on the couch together again, watching 'My Little Pony,' " she told TODAY.

Now family members and friends are calling for a cure for DIPGs.

“It is with a heavy heart to say our Princess has left us,” according to a GoFundMe page that has raised more than $75,000. “We lost our beloved Braylynn on Monday to this treacherous disease that needs to be eradicated.

“The donations will go to planning her funeral and to other families fighting this disease and some of it will be going to research to help find a cure. We do not wish this pain upon anyone. We may not be able to bring her back, but she may be able to help other babies from dying in the future. Thank you everyone for your thoughts and prayers.”

Posted by Ally Parker on Friday, January 12, 2018