Possible Clues:

• New arrivals of the 1950s
• Parents of Xers, perhaps
• Gen Xers' parents
• Gen Z, millennials, Gen X, ___
• Male kangaroos
• Gen-Xers' rearers
• Post-WWII babies
• Sixtysomethings, say
• New grandparents, probably
• Post-W.W. II demographic, informally