Since her heart transplant, 9-month-old Kara Duclos has become more active; she recently rolled over for the first time. (COURTESY PHOTO)

But while Kara is not out of the woods, she has overcome one great obstacle. For on Jan. 11, even as her swollen heart began to press against her lungs, Kara received the heart transplant she needed. And while she contracted a respiratory virus after the transplant, relatives said Kara is now home from Boston Children’s Hospital.

“She’s doing well. She beat that again. The kid’s a fighter,” said Rebecca Duclos, Kara’s aunt.

She recently rolled over for the first time, and took fiercely to a four-ounce bottle, something that she could not do before.

Kara, whose parents Eric and Julie live in Concord along with her sister, Samantha, was born with a severe congenital heart defect known as hypoplastic left heart syndrome. The left side of the heart and some major blood vessels don’t develop as they should. In some cases, a series of surgeries can fix the problem; in Kara’s case, a transplant was needed.

A few months ago, a heart was available for Kara, but repeated blood transfusions had caused her body to produce too many antigens, substances which heighten a person’s immune system. It complicated the search for a new heart, but one was eventually found.

After the transplant, Kara contracted respiratory syncytial virus, or RSV. This is a common infection among infants, though it can cause serious trouble in the lower respiratory tract. But Duclos said Kara’s prognosis is good.

“It’s amazing. It is such a miracle. It is such a miracle . . . it’s just incredible how far she’s come within a few weeks,” Duclos said.

In the near term, Kara will have to go back to Boston every two weeks for regular checkups. She will also have to stay at home. The anti-rejection drugs have so weakened her immune system that even a common cold could prove quite serious.

As for Kara’s parents, Duclos said they are exhausted and tired; but they too are doing well, just wanting normalcy. They’re also able to take heart in those simple things Kara can now do, she said.

“To them, it’s so much bigger than to us (with) our own kids. It makes a difference in your life, it really does,” Duclos said.

She also spoke about the wonderful gift of the heart itself, and hoped news of that gift would encourage people to become organ donors. The family is thankful too for all the support from the community, which through their long struggle has offered both its prayers and help.

The Duclos family has health insurance, but the costs related to Kara’s care were still overwhelming. One fundraiser in November raised more than $19,000 for Kara’s treatment. Smaller efforts have also raised some money: students at Jewett Street School, for instance, raised hundreds of dollars in small change for Kara.