Kaczynska's death Thursday was announced by Law and Justice, the conservative party led by Jaroslaw Kaczynski. The cause of death was not given but Kaczynska had been ill for several years.
The sons were openly attached to their mother and credited her with playing a strong role in shaping their political views and decisions.
For a time the two held the country's top political jobs simultaneously—as prime minister and president—and she was sometimes present with them at ceremonial events. The closeness of the family was also a way they expressed their attachment to traditional, Roman Catholic family values.
They had credited her with shaping their deeply conservative and patriotic world view, one that is marked by deep suspicion of Poland's historic foes Germany and Russia.
It's a view shaped by the experience of suffering during World War II, when Poland was carved up and occupied by Germany and the Soviet Union. Kaczynska herself was active in the anti-German resistance, giving first aid to wounded soldiers.
"Her descriptions of war, conspiracy, battles that her older friends took part in, and finally, her own involvement in the conspiracy, made a huge impression on me," Jaroslaw has said, according to the TVN24 news outlet.
Kaczynska's fate intersected with that of her son Lech, who was Poland's president when he died in a 2010 plane crash in Russia along with his wife and 94 others, including many of the country's top political and military leaders.
In the weeks before the crash, Kaczynska was in such a critical condition with heart and lung problems that the president had canceled foreign trips to be by his mother's side.
Polish media reported that Jaroslaw had also planned to be on the ill-fated flight but stayed home to be with their mother.
For many weeks after the crash she had no idea her son had died, with doctors asking the family to spare her the news until she was better.
Jaroslaw finally broke the news to her six weeks later, a devastating shock to her and a painful moment also for Jaroslaw, who has mourned his brother visibly, wearing black suits exclusively to this day in public.
Telling her "was the most difficult moment in Jaroslaw Kaczynski's life," a former aide, Elzbieta Jakubiak, said at the time.
Lech and Jaroslaw Kaczynski first entered the public spotlight as child movie stars in a 1962 hit film, "The Two Who Stole the Moon," about a pair of troublemakers who try to get rich by stealing the moon and selling it. Their mother, who then worked as a Polish language teacher at a Warsaw high school, gave up her work for half a year to be with her sons during the filming.
That was the end of their film career, however, and they went on to study law.
In the 1970s and 1980s, the brothers were activists in the anti-communist opposition and served as advisers to Solidarity founder Lech Walesa. After the fall of communism, they were active in political life in the young democratic state. They eventually formed Law and Justice, now the country's main opposition party.
Both brothers drew criticism from many quarters. In European Union circles, their nationalistic policies have been seen as euro-skeptic, and their suspicion of Germany and Russia has been criticized abroad—and by some Poles who feel their views are overly focused on the past.
Their mother said once when her sons were serving as president and prime minister that she was proud of them but that criticism of them was hard to take.
"Some of the comments and the attacks hurt me," she said, according to the news agency PAP.