User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-6064271-20130812120427/@comment-3146930-20130812172439

I think Sammy was 16 when Hazel was 13, so he was close to 70 by the time Leo was born. Lets say Sammy had his son at 25, then if that son had Esperanza at 20, Sammy would still only be about 45. Then Esperanza already had a degree by the time she had Leo, so she was most likely around 25 when she had Leo, meaning Sammy would be exactly 70. It works. I mean my mom was only 19 when she had my older sister and only 22 by the time she had me, so a great-grandfather at 70 isn't that hard to believe.