Wealth:
One day our kid saw Quicken's portfolio summary screen and uttered the observation "Holy #$%@, is that how much money we have?!?" I differentiated with "We parents have money, you don't" and then explained that what looked like a lot wasn't very much when it had to last for as long as 80 more years.
I also told her that what we can afford is a lot different than what's worth having. And she's always participating in our discussions about saving money, shopping hard, and living simply.
So she knows that we're doing OK. She realizes that while we'll cover her child-raising necessities, her life's luxuries are gonna come from the income that SHE produces. And we've told her that there won't be anything left when we're gone.
ER:
She knows we're always there for her. Field trips, projects, homework help, and other assistance are almost always available. She knows that we're much better rested and much less likely to snap with irritation (like the occasional good ol' workday). She knows that we have plenty of time to do things by ourselves and to teach her our skills. She knows that we'll help her resolve her school problems, but whining about school will just result in our offer to homeschool!