Sen. John McCain made a huge impact on countless people before his death — especially his 106-year-old mother, Roberta McCain.
A close McCain family friend tells PEOPLE that Roberta is “incredibly proud” of her middle child, the longtime politician and decorated war veteran who lost his battle to stage-four brain cancer at the age of 81 on Saturday.
“Roberta was his biggest supporter and the leader of his fan club. She was incredibly proud of him,” the source says. “His mommy loved him. He knew that.”
As Roberta grieves the loss of her son, the source points out that she “is a very strong woman,” noting the centenarian’s age as proof.
“She is all there, mentally, and is still going strong at 106,” the friend tells PEOPLE. “She outlived her 81-year-old son. That tells you a lot. But it’s a tough blow to bury your child.”
The insider adds that while Roberta did not travel to Arizona following Friday’s news that her son would be ceasing medical treatment for glioblastoma — the most aggressive form of brain cancer, with which he was diagnosed in July 2017 — the two did speak on the phone recently, and she knew the extent of Sen. McCain’s illness.
“I can only imagine what she’s going through,” the friend says of Roberta through tears.
The source tells PEOPLE that Roberta and Sen. McCain’s first wife Carol still keep in touch and have frequent conversations. (The two divorced in 1980 after 15 years of marriage and share three children: sons Douglas and Andy and daughter Sidney.)
“John never stopped loving Carol,” the insider says, adding that the exes spoke regularly before Sen. McCain’s death.
A close family friend revealed exclusively to PEOPLE on Friday, “Roberta is 106, but she’s spunky. She knows he is ill.”
Roberta has been a vocal supporter of her son’s political efforts over the years. At 96 years old, during Sen. McCain’s 2008 presidential campaign, she gave a speech to campaign workers, captured by CSPAN.
“Johnny is going to be the president of the United States and he’s going to keep the traditions … and the standards high,” she told the crowd, receiving applause.
“All we want is a world where we can raise our children, have a chance at prosperity and happiness, and we can vote any way we want to,” she continued before ending on a sweet note. “I can’t thank you enough … I wish I could kiss each one of you on the cheek. If I get a chance, I will.