Lily Healey doesn't have arthritis. But as an integral part of Sister Power, her mom says she's become a bit of a spokesperson for the disease — and for her older sister.

Lily, 8, has joined her older sister, Mya Healey, in a fundraising effort to give back to the Arthritis Society. In the two-and-a-half years that they've been fundraising, the pair — with some help from mom — has brought in more than $10,000.

The sisters call their fundraising group Sister Power, and they're continuing their fundraising efforts throughout the winter ahead of next year's Walk to Fight Arthritis in Paradise.

Healey sisters sister power

Lily Healey, left, and Mya Healey on their first Walk to Fight Arthritis in Paradise in 2015. (Submitted by Mandy Healey)

"They're a team in everything, they're each other's best friend," said Mandy Healey, mother of the two girls. 

"It's wonderful to see that they can both do this together, and that Lily is so willing to help Mya in any way that she can."

'They're a team in everything.' - Mandy Healey

Mya was diagnosed with juvenile arthritis when she was two. For the 11-year-old girl, it means stiffness in her joints, cataracts and inflammation behind her eye.

"I didn't know it existed when Mya was first diagnosed," Mandy Healey said. "It was just something I thought was a condition you got when you were older."

"As a parent it's frustrating, because you want to do everything you can for your child, and this is something that's beyond my control. I can't fix it."

Mandy Healey sister power fundraiser

Mandy Healey says Mya's diagnosis is part of the reason she is a strong girl. (Garrett Barry/CBC)

With medication, Healey said Mya can manage her symptoms fairly well, but it's hard for her to keep up with kids her own age and she has developed a selective mutism, which makes it hard for her to speak with people outside her inner circle.

'It's helping people get better.' - Lily Healey

"It's really difficult for her to try to explain what's going on on the inside, when people can't see it on the outside," Healey said.

"Lily has always been Mya's spokesperson, she talks for Mya often. She's a very proud little sister."

Steve Champion Medicine Shoppe

Stephen Champion, the pharmacist and franchisee at the Medicine Shoppe in Grand Falls-Windsor, says he has gotten to know Mya and Lily since he began working with their mom and wanted to help out with their fundraiser. (Garrett Barry/CBC)

The girls' latest effort is taking place at the Medicine Shoppe in Grand Falls-Windsor, Healey's workplace. For this season, the pharmacy will donate $1 from each flu shot to Sister Power.

It's a gesture from the pharmacist and franchisee, Stephen Champion, to his employee.

"It's a small pharmacy we work in. We work a lot of hours together, so we've gotten to know each other over the past ten months," he said. "I see how passionate Mandy is about juvenile arthritis and all the work that her and her daughters put into Sister Power, and I thought it was the least I could do." 

"It's wonderful to know that he cares beyond just the nine to five," adds Healey.

Mya Healey change challenge

Mya Healey poses with the change collected through her Change Challenge in 2016. (Submitted by Mandy Healey)

Since 2015, Mya and Lily have been walking and fundraising for the Walk to Fight Arthritis in Paradise. They've helped their mom with an online auction, a ticket sale on a quilt, and last year they came up with their own idea — the change challenge.

"For the whole month of May, they saved up their change. They dug through piggy banks, they dug in the sofa cushions, out in the car, and they raised a lot of money that way," Healey said.

Why all that effort? For Lily, speaking on behalf of her sister, the motivations are simple.

"[Because] it's helping people get better," she said.

Lily Healey talks about her older sister's arthritis diagnosis1:11

"I like helping people get better…so they can someday be like us." 

Healey said the fundraisers have helped give her daughter's a sense of pride.

"What I hope it means to them is a sense that they belong to something bigger. They're a part of changing the way people look at arthritis," she said.

"I hope that it helps give them pride in knowing that they're helping not only Mya, but children and adults like her."