I first encountered Warhammer: Fantasy during the fifth edition while visiting a gaming store back in 1999 when I was in high school, but didn't buy my own miniatures until the sixth edition, around 2001. I was an avid console gamer back then, and still are, but the hobby aspects drew me to try Warhammer as well as I like DIY building (mainly fly lures and other fishing equipment back then).
I don't have my own children, but many of my hobbyist friends have got their children into the hobby pretty spontaneously. Starting from "painting stuff along with their daddy/mommy" and eventually getting some games in as well when the children are old enough to understand the rules. Not all of them keep at it, but at least they've been interested enough to try.
Not familiar with Warhammer: Adventure series, but I do own many of the Fantasy and 40k novels (like the Gotrek & Felix and the Horus Heresy series).