alt Hacker News27 a month?
So, a little less than one a day? That seems eminently doable -- I read more than that in my teens, considerably more sometimes, for years at a time. (Of course I had no internet to distract me: my teens were from about 1977 to 1986.)
I have read the Lord of the Rings trilogy 5 times, Kim Stnaley Robinson's Mars trilogy 6 times, and the entire Frank Herbert _Dune_ series twice. In my early teens, if under time pressure, several times I read about half a dozen novels in an afternoon.
For a retired professional? Sure. I'd be surprised if she couldn't.
Around 1997-1998, I was freelance, not working a lot, and lived with a judge of the Arthur C Clarke award. I read pretty much all the new SF published in the UK both years. A couple of hundred books a year, while working.
Let’s take your six novels in an afternoon. Il be generous and give you the entire six hours for six novels. Even at a relatively low page count of 250 pages each novel it would mean you read more than 4 pages a minute, for six hours straight. And if any of those six novels had more pages (very likely given the books you name drop) you could easily need to double the number of pages read per minute.
So at best you skimmed six books in an afternoon, which IS a time-honoured tradition by school kids who have reports due.