"And just like that our perfect world was shattered," Adrianne Stewart tells PEOPLE
A little over a year ago, Adrianne and Jason Stewart adopted 3-year-old Maria, who was born without legs or arms, from the Philippines.
The couple — also parents to two biological daughters Breanna, 13, and Eva, 11, and one adopted son, Joshua, 6 — felt like their family was finally complete.
But just as Maria was settling into her new life, complete with rigorous physical therapy and preschool classes, in their West Jordan, Utah, hometown, the Stewarts were hit with devastating news.
Joshua, who was adopted from the Philippines five years ago, was diagnosed with acute myeloid leukemia.
“And just like that our perfect world was shattered,” Adrianne, a stay-at-home mother, tells PEOPLE. “Our entire world was turned upside down.”
The couple first started looking into adoption after Adrianne endured major complications during both of her daughters’ births.
Jason had previously visited the Philippines and loved the culture. After years of paperwork and interviews, the family was matched with Joshua in 2012 and he quickly became a part of the family.
“When we saw Joshua for the first time, we knew he was our son, he was such a cutie pie!” says Adrianne. “He has a condition that can cause him to be anemic, but nothing serious, cancer was not on our minds at all.”
The parents had no idea that their son would be diagnosed with a rare form of leukemia only a few years later.
The Stewarts expanded their family a year-and-a-half ago with Maria’s adoption. She was born without arms or legs, though the family hasn’t put her through any testing to determine why.
“Maria doesn’t understand what’s going on with her brother,” explains Adrianne. “She’s worried though.”
In April, Adrianne and Jason, a cable technician, took Joshua to the doctor after he was unable to kick a fever. The urgent care directed the family to the hospital for more tests.
“They ran a leukemia test and it came back positive with signs of a really aggressive cancer,” says Adrianne. “So with aggressive leukemia, comes aggressive treatment.
“I was in shock, I said, ‘This can’t be happening to our healthy kid! Why now?’ I didn’t’ want to believe it for a while.”
Doctors gave Joshua a 65 percent chance of survival.
“It’s hard to look at that percentage and think positively,” says Adrianne. “We’re just trying to take one day at a time.”
She adds: “Joshua knows he’s sick, but not the extent of it. We chose not to tell him that sometimes kids can die of cancer. We don’t want him to have fear or sadness.”
The Stewarts, who have a GoFundMe page set up, are hopeful about Joshua’s future as he undergoes chemotherapy.
And Adrianne’s even got a special helper during their frequent hospital visits.
“Maria loves being there for her brother,” says Adrianne. “She practices using her wheelchair in the hallway of the hospital. We’re all in this together.”