WYLIE, Texas -- It would seem hard to imagine: a blessing, disguised as a nosebleed.

CBS DFW reports the story began in January of 2013, when then-14-year-old Crystal Enns of Wylie, Texas, had such a bad nosebleed that she didn't go to school. Her parents suspected that something was wrong, but they never imagined it would lead to a serious diagnosis -- a rare kidney disease that would require a transplant.

"When he [the doctor] first said I would have to have a transplant, I didn't want to talk about it," says Crystal, now 17 and entering her senior year of high school. "I didn't want to think that that would have to happen."

Crystal Enns. KTVT

Both parents have matching blood types and could be possible donors. Crystal's mom, Cristy, began the intensive screening process first. That's when the already worrisome situation took an even more troubling turn. Doctors had discovered a suspicious spot on her kidney.

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"To find out at the very last minute with the last test that we couldn't [donate] was devastating," recalls Cristy. So her husband and Crystal's dad, Mark, was screened as a possible donor. The bad news was about to get worse: He had kidney cancer.

"The doctor that called said, 'This is lights and sirens. This is top of your 'to do' list. This needs to come out right away. This doesn't look good,'" says Mark. He was stunned.

"The idea is that we're going to go in and do something that can be life-saving for our daughter, only to be told 'this may have saved your life,' because I would never have been tested otherwise."

Actually, both of their lives may have been saved -- along with their daughter's.

"They went back and did another MRI on me," says Cristy, "and it had grown. The crazy thing was, it ended up being the same type of kidney cancer that Mark had."

After a pause, she adds, "It's scary to think about. Very scary to think about. We've got four kids... to find out you have kidney cancer when you're 39 years old is not something you ever think will happen. So we're extremely grateful."

Fortunately for Crystal, her aunt, Cristy's sister, was a perfect match and was able to donate a kidney in April. And the impact was instant.

"The morning after the transplant she woke up and she said 'I'm not nauseous!'" recalls Cristy with a huge smile. "She could eat, she was hungry... it was such an answer to prayer."

Oddly, doctors say it turns out that Crystal's bloody nose, which started the entire chain of events, had no connection to the condition that led to her transplant.

"It happened to be a red herring that allowed us to figure this out because of other symptoms at that time," says Albert Quan, MD, a Pediatric Nephrologist at Medical City Children's Hospital. Dr. Quan is also quick to reassure parents that a typical nosebleed should not be a cause for alarm, noting that Crystal's particular type of kidney disease is "very, very rare. I've only seen about two or three in the last 20 years."

Now, the talented teen musician, who for much of the past two years had been too weak to stand and sing with her choir, can get back to doing the things she loves, knowing that her parents are healthy because of her. "That's amazing," she told CBS 11 reporter Robbie Owens.

The Enns family says the entire experience has helped reinforce their faith.

"You try to think, 'Where's the good in this, as people of faith? What am I supposed to learn?'" asks Mark. "We got to see the good side."