A special night for a little girl who has been through a rough time recently. Five-year-old Penny Armstrong was diagnosed with leukemia in 2016 and has been in the fight of her life ever since.

Along with the usual splish and splash, there was a bit of magic at the Mountlake Terrace Pool Saturday night. A special pool party brought Penny and her family out for a swim.

“She's always loved to swim. She loves to be outside, and she just loves mermaids,” her mom Abbey Armstrong explained. “She loves the colors and the magic about them."

That's where a very special group stepped in to help.

“This is the Seattle Mermaid Pod because we all just come together because of our love of mermaiding" Jen Page explained.

There are about 100 members and they just added another to the pod, giving Penny her own tail.

Penny is currently battling leukemia and undergoing treatment through Seattle Children’s Hospital.

“There's not a lot of stuff she can do," he mom explained. She's been in chemo for more than a year and still has 10 months to go.

Her family was so touched by the group who made the night so special for Penny.

“I'm just blown away. It means a lot,” she said, wiping away tears.

The mermaids were touched as well.

“Seeing Penny put that tail on, it was watching a childhood dream come true. It was so sweet,” Page explained.

They hope the experience will give her the extra strength she needs to continue her fight.

“She's completely part of the pod. Maybe we should rename it the Penny Pod," Page said.

Armstrong's mother hopes sharing their story will help generate more support for pediatric cancer research. It doesn't get as much funding as adult types of cancer, and she wants to help all children facing it.