Madalayna Ducharme is recovering well from a procedure aimed at saving her from a rare and potentially fatal genetic disorder.
Just last week, doctors discovered Madalayna's two-year-old brother, Henrik, was a bone marrow match that could help in her battle with malignant infantile osteopetrosis.
The condition can cause a host of health problems, including recurrent infections as well as hearing and vision problems.
Doctors transplanted Henrik's bone marrow Friday. It could be at least two weeks before anyone will know how successful the procedure was, according to Tamara Ducharme, the children's mother.
"So far, so good," she told CBC News.
Henrik also seems to be doing well after the procedure.
"He's got two little pokes on each side of his hip, one on each side," Tamara said. "He was running around and playing and happy. You wouldn't even know he went through anything like that."
At least 1,300 people in Windsor came out and got swabbed to see if they could help Madalayna.