In college in 1948, so wealthier demographic, and white. Raise that average age at death. They also survived to at least 18.

White and female alone puts average lifespan at 78.1. "2.91 years for women who are among the top 5 percent of income earners in America" So ballpark 50% made it to 82. In the total US population nearly 30% of females live into their 90s.

This falls of quickly though, only 16.7% of women make it to 92. and only 6.4% to 96; our range assuming typical college ages. (Per SSA tables)

Based on that, out of roughly 70 women aged 92-96, 3 to 4 will be alive today