Then, the organization went on hiatus in Georgia when four group members were charged with assisted suicide. Awash with anxiety, the 43-year-old Caldwell filed a lawsuit last week asking a federal judge to let the group assign her an "exit guide" who could hold her hand and guide her through her final hours if the pain of living becomes unbearable.
"It is not the illness I fear, it is the suffering it causes," she said. "Final Exit Network provided relief and compassion to people like me."
She claims in the lawsuit that Georgia's assisted suicide law is vague and unconstitutional. She contends it violates her free speech rights because it blocks her from seeking the advice of right-to-die groups.
Caldwell has Huntington's disease, a genetic disorder that usually leads to dementia, difficulty speaking and involuntary movements. The disease, which afflicts an estimated 30,000 people in the U.S., is passed from parent to child, and there's no cure. Most people die about 15 to 20 years after developing symptoms.
Caldwell's grandfather and uncle had it, and her mother grew so fearful in 1985 that her children would develop it that she shot and killed Caldwell's 19-year-old brother and then tried to shoot Susan, who was then 18, but missed.
Caldwell's mother was sentenced to life in prison, and was diagnosed with the disease while serving time. She was released after a 1994 retrial found her not guilty by reason of insanity, in part because of her daughter's testimony.
Glenda Caldwell died in 2001 and a year later, Susan Caldwell was diagnosed. By August 2008, she said she was so concerned her extended family would be burdened by her for years that she attached a helium tank to a hood and tried to kill herself, a method outlined in a best-selling suicide manual by British author Derek Humphry.
It's the same method used by the Final Exit Network, though they recommend having "exit guides" to help. The group's members have bristled at prosecutors' use of the term assisted suicide, saying they don't actively aid suicides but rather support and guide those who decide to end their lives.
Critics say the group sends a dangerous message to society.
"It says that we'll look the other way when not-so productive people commit suicide, that they are burdens and that society isn't that troubled to see them die," said Stephen Drake of the group Not Dead Yet.
Georgia's law makes it a felony for anyone who "publicly advertises, offers, or holds himself or herself out as offering that he or she will intentionally and actively assist another person in the commission of suicide and commits any overt act to further that purpose."
Caldwell's lawsuit claims it violates her free speech rights because instead of criminalizing suicide or assisted suicide, it outlaws people from publicly speaking about assisted suicide and then participating in the death. That means people who only hold the hand of a terminally ill person as they end their life could be prosecuted, said Caldwell's attorney Cynthia Counts.
Georgia Attorney General Thurbert Baker's office and Georgia Gov. Sonny Perdue's office declined to comment. But prosecutors have countered that lawmakers intended to ban assisted suicide when they adopted the law.
Caldwell's previous guides from the Final Exit Network were then-group president Ted Goodwin and member Claire Blehr, who assessed her case and encouraged her not to end her life.
"They challenged me to see the quality of life that remains, and made me think about how hard this will be on my family when it comes and how important it is for me to fight for as much time as I can have with my family and friends," said Caldwell.
But her steadiness shattered in February 2009 when Goodwin, Blehr and two other members of the group were charged in the death of John Celmer after an eight-month investigation by the Georgia Bureau of Investigation.
Investigators said Celmer was recovering from cancer when the group sent exit guides to his home to show him how to suffocate himself using helium tanks and a plastic hood. Authorities have also raised questions over how carefully the group, whose leaders claim to have been involved in about 200 suicides, screened potential members.
The four group members have pleaded not guilty, and their attorneys contend the charges are baseless.
Caldwell, who is now having trouble swallowing, wants Georgia's law overturned because she believes she has the right to die. And she believes she has the right to seek the group's help if she wants to end her life.
"People are going to commit suicide regardless, and the Final Exit Network offers a peaceful and painless way to die with dignity," she said. "Having it be peaceful and dignified, and having a compassionate and supportive person who is there to hold your hand and be emotionally supportive of you, is critical."