None of the cousins were orphaned at age 12. They ranged in age from 3 to 7 when their parents died in late 1965. Their ages when orphaned certainly doesn't negate what you're saying, I just wanted to clarify they were a lot younger than 12.
"Then, in 1958, Lou and Beverley adopted a baby boy, Tim, and, as sometimes happens, Beverley became pregnant. She gave birth to Jeffrey in 1960, Kerry in 1961 and Dana in 1962."
https://torontolife.com/from-the-archives/barry-sherman-bitter-pill-from-the-archives/