The scenario you describe is too close a match to the 1844 Millerite fiasco to be a coincidence. I think your mother mixed up the stories.
However, William Miller's cockeyed ideas gave rise to several Adventist type religions, including the early influences on the JWs. So, although the story is not specifically accurate, with a few corrections is still pretty significant.
In the late 1960s and early 1970s, JWs predicted that Armageddon would come in 1975. As the day approached, they backed off slightly, but there were many followers who took them at their word and adjusted their lives according to their belief in the imminent end. They did things like selling possetions, foregoing education, spending their savings, and even putting off dental work. However, this behavior was mostly individual in nature.
Similarly, there were major disappointments, such as 1925 (when "Millions now living will never die") and 1914, which was the biggest failure of them all.