I unfortunately only have anecdotal evidence that 60h is not implausible.
Me and my wife have two kids and share most of the household work, it's not an even split (she does more). I would say that on average we both work from the time we get back home from work until the kids sleep, ~4hrs later. In addition to that, one of us probably spends some 30 mins each morning getting the kids ready for school. Saturdays and Sundays typically involve two cooked meals per day plus any bigger household work that the weekdays won't fit. So I guess we spend some 60h/week on chores.