Perhaps she means she is 67 now, not when she was in grade school. In 1967, I think nearly all schools had cafeterias.
There are still a few of us oldies around. Very few 67 year old “children” were in grade school.
And you'd be wrong. That year was the very first year for the first cafeteria in the brand new junior high school of my youth. The elementary schools were strictly a brown-bag or go-home lunch situation. The high school was downtown with access to lunch counters or get in your car to go to a drive-in or brown-bag. I write all of this from first-hand experience with each as I was part of the first group to experience the new cafeteria in 1967 as a 7th-grade student in that mid-sized Kansas town.
OH!
The coincidence of math and time?!