Rita's parents, works foreman Ludwig Glasner and his wife Katharina, became Jehovah's Witnesses in 1933. She was exposed to Nazi persecution for the majority of her childhood and youth. When she was seven years old, both of her parents were arrested – though not at the same time – for supporting a leaflet campaign. At school, Rita was subjected to reprisals because she refused to give the Hitler salute. For several years, she transported illegal texts as a courier. When she was baptized as a Jehovah's Witness in 1942 at the age of twelve, she was aware of the possible consequences. In 1943, while Rita's father was working abroad for his brother-in-law's construction company, which had been forcibly subordinated to the Wehrmacht, her mother was arrested again because she was carrying a copy of the “Watchtower” with critical remarks about Hitler and the war.
Rita was now left to her own devices in the middle of the war. After three months, she was taken in by a neighboring family. Rita's mother was interrogated several times by the Gestapo under torture. To increase the pressure on her mother to incriminate herself and other Jehovah's Witnesses, Rita had to listen to an interrogation in the next room. After being held in Munich-Stadelheim prison, Rita's mother was sent to Weilheim prison, and then transferred to Berlin-Moabit because her trial before the People's Court was imminent. Rita was present on August 29, 1944 when the death sentence was pronounced for undermining military morale and receiving and passing on anti-regime writings from Jehovah's Witnesses. On the same day, the sentence was commuted to seven years in penitentiary. Katharina Glasner was sent to Waldheim Penitentiary.
After her liberation on May 8, 1945, Rita was able to return to her parents. In 1948 she married Erwin Berger from Munich, with whom she lived for almost 60 years until his death in 2008.