SALT LAKE CITY -- It’s a reunion between a 5-year-old girl and the person who saved her life by giving her a piece of themselves.

This bubbly child’s life was very different before a stranger stepped in to offer the gift of life.

A year ago when we met Lily, she was a very sick little girl.

Her family moved to Utah from Caldwell, Idaho, to wait for a kidney.

After months of waiting, Lily's mom, Amanda, got proactive and found a donor on Facebook last October.

“I met her through social media and I was afraid of the unknown,” Amanda said. “She did the testing in New Mexico and she was a match.”

After being tested, Jenna Allen flew to Utah and donated her kidney to a young girl, who was then a complete stranger.

FOX 13 News caught up with Jenna last month when she surprised Lily for a quick reunion at the Ronald McDonald House.

Jenna said she is delighted she was able to help Lily live a happy and fulfilling life.

“I feel great, just overwhelmed with emotions and the reason why I did it is the way she's active and moving and able to be outside the hospital; just exactly what I expected,” Jenna said.

Lily's mother says the transformation she has seen in her daughter is amazing.

“She is happy all the time,” Amanda said. “She has so much energy, she's a whole different child. Before she had the transplant, all she did was sit down and she was so tired. She would take three naps at least.”

Jenna said the day of surgery she was a bit scared but hasn't had any health problems since and is so very glad she is a donor.

“I think a lot of people don’t realize the struggle it is for people in situations like Lily, waiting on the list and waiting for a transplant,” Jenna said.

Living donors can remain anonymous but in this situation, the family and the donor are more than friends.

“We love her unconditionally,” Amanda said. “There's no way we could say thank you enough. Her husband and her kids, they’re our family now.”