Things were already difficult last year for the Colantonio family of Braintree.

The elder daughter, Nicole, 19, was going through chemotherapy. She had been diagnosed with stage 4 lymphoma in August 2011. But by December, only a few months of chemotherapy and several weeks of radiation remained. There was a light at the end of the tunnel.

That was when the younger daughter, 14-year-old Katelyn, started mentioning that she wasn’t feeling well.

“We thought she had a stomach virus. They did some tests and said they didn’t see anything,” said Janice Colantonio, the girls’ mother.

By January 2012, Katelyn’s cold hadn’t gone away, and when she came home from school with ankles swollen like balloons, Janice knew something was wrong.

After another trip to the doctor’s, Katelyn was sent to Children’s Hospital in Boston. Soon the family found out that their youngest had acute kidney failure.

In an instant, the outgoing, straight-A student who loved playing tennis, performing in plays, and singing, was bedridden, with life as she knew it put on hold.

She was admitted to the hospital for two weeks, and was soon undergoing dialysis treatments three times a week.

Although she has since come home, much else has changed for Katelyn.

She takes several medications in the morning, and has had a port installed in her chest for the dialysis, which prevents her from showering or swimming.

Her diet has needed to be changed as well, as Katelyn is prohibited from drinking many liquids and foods.

While Katelyn learned to cope with a new way of life, her family was committed to giving the teen new hope through a kidney transplant.

“You have to be blood Type O to be a match for Katelyn,’’ Janice said, and only her husband, Jimmy, was.

According to Janice, the testing process has several components, where doctors compare blood types and tissue samples. Tests were going fine, and a transplant was scheduled to take place within a few weeks, but one of the final tests proved Katelyn’s dad wouldn’t be able to donate.

“They make sure you’re a good tissue match, but go on to make sure you will have a healthy life with one kidney . . . and he was going through all of that until the last one that ruled him out. It was devastating for us,” Janice said.

The family said it is now back at square one, and is looking for members of the community to come forward and be tested. With luck, someone’s kidney might be a match.

Last Tuesday, a Facebook page (www.facebook.com/kidneyforkatie) was created to get the word out, and a blog started to shed light on the family’s situation.

Since then, several people have come forward, and the family hopes more might volunteer.

“We got together last night. . . and [Katelyn] said to me, ‘Mom I feel really sick.’ I think it’s just her concern about someone having to give their kidney to her. It’s just a lot emotionally,” Janice said “[But] I do have a lot of hope.”