Her son Jean Wabafiyebazu, 17, died Monday after police allege a drug deal inside an apartment complex in Miami's Coral Way neighbourhood ended in an exchange of gunfire.
Dubé, Canada's consul general in Miami, released a statement Thursday expressing "our most profound thanks for the outpouring of support we have received in the last few days."
Another teen, identified as Joshua Wright, 17, died in the shootout. A third teen was wounded.
Dubé offered condolences to Wright's family and to others affected by the incident.
"Your grief is our grief," she wrote. "We can only hope that, in time, we will find common purpose towards diminishing the causes of such violent crimes."
Teen allegedly threatened to kill officer
Dubé's son Marc was arrested Monday and remains in police custody on suspicion of being an accessory to murder. But he has not been formally charged, Florida state authorities said.
"The case has just started," said Ed Griffith, spokesman for the Miami-Dade Office of the State Attorney. "We're evaluating all of our legal options at this point."
Legal authorities also must decide — if Wabafiyebazu is charged— whether to try him as a youth or an adult.
Investigators also accuse Marc Wabafiyebazu of threatening to kill an officer, saying that he would shoot him in the head, according to an affidavit obtained by CBC News.
Diplomatic plates on car
The two brothers had moved to Florida recently to be with their mother, who became the consul general in Miami six weeks ago.
They reportedly used her BMW – equipped with diplomatic licence plates – on the day of the shooting.
A spokesman for Foreign Affairs, Trade and Development Canada said the car is Dubé's personal vehicle and not government owned.
Department officials are providing Dubé and her family assistance, according to department spokesman John Babcock. Louise Léger has been named the acting head of mission on an interim basis.
Dubé asked for privacy while the family grieves "in this difficult time."
"For now, we just want to be there for Marc, our incredibly caring son who loved his brother very much, and to say goodbye, ever so tenderly and quietly to Jean, our love," she wrote.
On Wednesday, the teens' father, Germano Wabafiyebazu, who is divorced from their mother, said he had warned them about the potential risks of life in Miami and wanted them to stay in Ottawa, where they were born and raised.