Not the parent, but that's less than 1 book a week, which I often do.

If your average non-fiction book takes you ~12 hrs to read, that 3 nights of 4 hours of reading. In other words, if reading is a main hobby it's totally doable. (Also if you have an hour commute to/from work on the subway or train, that's 10 hrs/wk right there, or... 40 books a year.)

Also, I personally find that non-fiction is much faster to read than fiction -- in fiction, you want to savor and appreciate each sentence as it paints a world you don't know. In non-fiction, there tends to be a "lot you already know" when reading that you can read quickly, especially when you read multiple books on similar topics. (E.g. reading about the Stanford Prison Experiment for the nth time, or an explanation of the Prisoner's Dilemma.)