Kaia has a rare autoimmune disorder. She is allergic to the sun, and if it is left untreated it can affect her muscles and her ability to walk.
"She goes through treatments once a week at CHOP, and then once a month she has a 10-hour treatment called IVIG at CHOP," said Dave Ettingoff, Kaia's dad.
So when the Make-a-Wish Foundation asked Kaia what she wanted, she did not hesitate.
"With the tree house she avoids the sun and it's really the perfect thing for her," said Ettingoff.
The labor and materials were donated by EDA contractors, who said designing something with a zipline and a climbing wall was a nice change of pace.
"We're used to doing buildings and now we're doing a treehouse," said Tony Melle of EDA Construction. "It was really nice to do this and the little girl has been so grateful and she has just been wonderful. I hope she enjoys it."