Now, she's on life support at UNC Hospitals.
"She's gravely ill," said Doctor Charles Van der Horst.
Van der Horst says the freshman took a turn for the worse while stricken with the H1N1 virus, and state-of-the art medical technology is keeping her alive.
"She's got a very strong heart," said Van der Horst. "And she's young and that's in her favor."
Also in her favor are friends, family, even strangers, who are rallying behind her on Facebook. Thousands have posted messages - checking daily for Chason's parents to update her condition. This week, they write "things have been stable."
"I've really appreciated seeing people's comments such as, 'I haven't had the opportunity to meet you yet, but I'm praying for you,' and I just feel like that's so encouraging to the family and to Lillian," classmate Rachel May said.
May along with fellow classmate Will Barbour, say Lillian Chason's illness is the grief of their drama class.
"I sit next to her in drama 120 and I just think she's brilliant especially when it comes to drama," May said.
"A lot of people have really come together to go see her," Barbour said, "We all wrote, signed a note in our drama class …..sending our best wishes to her."
Lillian's grave condition - doctors say - is hardly uncommon. Her young age puts her in the high risk group.
"The important thing that the parents want to say is that it's important to get vaccinated," said Van der Horst.
Van der Horst specializes in infectious diseases and firmly believes the H1H1 vaccine prevents the spread of the virus.
"Protecting people like Lillian," he said.
Right now's a wait and see situation. The hope is Lillian's lungs will grow stronger and she will recover.
"I'm praying for her and I really believe that she's going to pull through," May said.
Anyone who'd like to wish her well can send cards or a note to the hospital or go to her Facebook page.