Educating adult children

HNW couple with a single child. It's been obvious my kid's entire life that we're better off than most, but we haven't been extravagant. Kid is now late 20's and a doctor, just started career, about to get married and figuring things out. No school debt or car debt and I still pay their car insurance and some small random things like cell phone.

But they have no real idea about managing money, just figuring it out on low early doc income and living in a HCOL city.

They have no idea of the scale of our NW and it seems wrong to surprise them with 10's of millions if we get hit by a bus. Doesn't help that the wife isn't great with money or paperwork 😜 since the kid would have to help figure things out if I go first. I do have a "if I get hit by a bus" package prepared but that would still be a lot to digest. We're also soon to be retired, getting a second home etc, so things will get a little more obvious.

Anyone find good resources on when/how to talk about future inheritance etc? And how much to help vs not so they can figure things out reasonably early on. I searched prior threads but most are about much younger kids. Just not sure how/when to broach it. On the eve of a wedding seems wrong.