Courtesy Jamie's Dream Team

At 5 years old, Brielle Kelly has seen more hardship than many people face in a lifetime.

Just days after she was born, Brielle's small intestine became twisted and its blood supply was cut off. The Duncannon, Pa., girl had to have her entire small intestine removed just days later.

In 2012, Brielle received a bowel transplant, and for a while it seemed things were looking up, but in January of this year, she was diagnosed with tumors on the new organ and had to have it removed, leaving her completely dependent upon a feeding tube.

The following month, as her mother, Tina Kelly, was preparing to bring her daughter home from the Children's Hospital of Pittsburgh, a routine CT scan revealed Brielle had cancer, a B-cell lymphoma that was present in her brain and liver.

Brielle has since been having chemotherapy. Wanting to do something nice to lift her daughter's spirits as her October birthday approached, Tina Kelly contacted Jamie's Dream Team, a Pennsylvania-based nonprofit dedicated to helping sick people's dreams come true.

Kelly initially hoped for a swing set for her daughter, but she got much more. On Saturday, Jamie's Dream Team treated Brielle to a fantasy weekend where she got the royal treatment.

On Saturday morning, Brielle, her sister, 7-year-old Alayna, her mother and grandmother were taken to a salon in Hershey, Pa., and had their hair, nails and makeup done. From there, they were transported by horse-drawn carriage to The Hotel Hershey, where 100 of the Kelly's family and friends had gathered to wish Brielle a belated birthday.

There was music and food, Brielle and Alayna's friends wore princess costumes and danced, and even Santa dropped by, Kelly told ABCNews.com in a Sunday interview.

"It was just really an amazing time," she said, adding that Brielle loved the fete so much that it took some of the sting out of having to go back to the hospital for more chemo this week.

"She's been smiles all day yesterday and today," Kelly added.

Jamie Holmes, who founded Jamie's Dream Team seven years ago after battling her own catastrophic illness, said she was touched by Brielle's story and gratified that the event went well. The family also spent Sunday at Hershey Park, she said.

"I've spent some time with Brielle before this party and I have not seen her this happy," Holmes said. "She was all smiles - the whole family was absolutely stunning."

Holmes estimated that the value of the weekend was about $10,000, and she added that many people in the area donated goods and services.

Though a recent scan indicates Brielle is free of cancer, she will receive "maintenance" rounds of chemotherapy, Kelly said. The girl also still needs another bowel transplant.

Even though she has a long way to go, Brielle's fantasy weekend has buoyed her spirits and taken her mind off "getting medicine that's going to make her sick," Kelly said, adding that, when she contacted Jamie's Dream Team she had no idea what could happen.

"What they've done for our family is just amazing," she said.