NORTH ANDOVER — Deb Swenson was teaching a class at the now-closed Bradstreet Elementary School when she got the phone call. It was Danielle DeLisle on the line and she was calling about her daughter Cassandra Dupont, a student in Swenson's class.

After four years of waiting, DeLisle said doctors had a liver for Cassie. She was due at Massachusetts General Hospital immediately for a transplant operation.

Swenson spent that night at the hospital with Cassie's family. The transplant saved the then 7-year-old's life and she was back in school within months.

"It was amazing," said Swenson. "She did so well. And they hoped with the transplant that it would also help her lungs, but it didn't. She has bad asthma. She's a mystery."

Six years later, DeLisle still considers Cassie her "miracle child."

Cassie, now 13, was born with a rare liver disease that doctors have struggled to diagnose. She also suffers from pulmonary hypertension, or high blood pressure in her lungs.

On July 22, Cassie was hospitalized after contracting the H1N1 flu. She has spent the last month on life support at Massachusetts General Hospital after her left lung collapsed.

Although she no longer has swine flu, DeLisle said fluid remains in her daughter's lungs.

After 17 days breathing a combination of oxygen and the anesthetic Isoflurane, Cassie is back on a regular ventilator, her mother said Thursday.

She began opening her eyes in response to the voices of family members this week.

"If they want to give me baby steps forward every day, I will take those baby steps and move along with her," said DeLisle.

DeLisle said Cassie's doctors are watching her closely to see if she can gradually be taken off life support and begin breathing on her own.

"It's up to Cassie," said DeLisle. "They're just trucking along with her. She's in charge. She's the coach, and she'll let them know how much to push her."

Before she was hospitalized, Cassie was just days from completing the sixth grade at North Andover Middle School. Those close to her are finding it hard to believe she's now faced with yet another life-threatening hurdle.

"Of all the obstacles Cassie has overcome with her health issues, it's just unfair that she's fighting for her life due to a virus," said Swenson, who lives in Haverhill and now teaches at the Franklin School. "I will never give up hope on Cassie. She's a fighter. I've seen her overcome huge obstacles in her life. I have to believe she's going to overcome this."

Cassie was new to North Andover Middle School in September, but now is a well-known student there, said special education teacher Kate Noonan.

"She's like the little mayor," said Noonan. "Everybody knows her. Everybody loves her."

Noonan participated in a fundraiser for Cassie's family earlier this month to help pay her medical expenses. Supporters raised nearly $1,000, she said.

"I'm going to continue to hope and pray that she gets better," said Noonan. "I believe in miracles, and Cassie is due for a miracle at this point."

Barbara Ann Donovan, Cassie's school nurse, said that when she learned Cassie had contracted the H1N1 flu virus she knew it would be a difficult battle.

"I knew it was going to be a long haul," said Donovan. "If anybody can, I swear to God, she can make it."

Like her mother, Donovan said Cassie is strong-willed and speaks her mind.

"Danielle and Cassie have sort of grown up together," said Donovan. "Danielle had her when she was very young."

DeLisle, a member of St. Michael Parish on Main Street, expressed thanks on Thursday for all the support her family has received.

"She's on every prayer list you can think of," said DeLisle.

Cassie's doctors and nurses also have been tremendous, she said.

"They cry with me," said DeLisle. "Every nurse in this ICU has shed a tear with me in the last month."