I’ve run lighter things with one of my kids, sort of “BW-adjacent”.
However, I think it depends on their ages (mine was under 10), and where they’re at, investment-wise.
I’d be tempted to have a bunch of pre-gens to get them started - maybe 6 or so, giving them a range of options to pick from.
I’d also be tempted to have fairly straight forward pre-gen concepts (maybe with a little twist in the back there, somewhere).
Depending on what you think they might be interested in, then, for instance, a “fighter” who was once a village guard, or an ex-pilgrim priest, or a neophyte(ish) wizard, who was born on the streets, etc.
I’d angle for solid concepts, but with one Lifepath that gives them a few unusual options and skills?
Then, good ol’ Hub and Spokes to get it all rolling.
I’d then be encouraging, looking for Help / FORKs they can provide, and showing them that a failed dice roll can be cool and interesting.
Making sure to announce the consequence of failure before the roll is great for this! I’d even, depending on the group, point to potential solutions.
e.g. “They’d lock you up in the side room. However, (fellow PC) Big Olaf does have a big hammer, and that wall doesn’t look too thick…”
I always love it when my players start muttering “and now I want to fail - that sounds really interesting!”