I might have already mentioned this on here a long while back, but in case I didn't, here's a pro tip that I learned from unfortunate personal experience with a family member's estate: PUT SOMETHING IN YOUR WILL THAT PREVENTS STUFF GOING TO AN ADULT ADOPTEE.
I'm not quite sure why this is a concern. You have money and leave it to a relative (let's say nephew). Isn't it his now? When he dies, wouldn't it now be part of his estate and go to whom his will dictates? So what if he wants to leave his stuff to a drunken friend? What if he had a feckless son? Would you try to take back what you willed beyond the grave?
Once you give a gift, doesn't it belong to the recipient?
Exactly. It's theirs to do with as they will, for good or ill.
On another note, an aunt of my wife died recently. She's always been reputed to be wealthy, with gobs of Krugerrands, etc.
My wife's worthless sister, who in her 50s still think the world revolves around her and her wants, has been sucking up to said aunt for the last couple of years as the aunt's health failed. This was so the aunt would give her all the money.
She's been playing the "I prayed and God told me to tell you to do {fill in the blank action that benefits her}." card ever since her dad died. When she pulled that on my wife, telling her that their recently departed father had appointed the sister as his spokesperson here on Earth.
"Oh, really? How did he do that? Did he phone you? Or send you a telex?" They haven't spoken since and that's been twenty five years or so. My wife won't put up with her crap and her sister knows it.
Anyway, the sister apparently overplayed her hand. She started telling the aunt that God had instructed her to tell the aunt to do {fill in the blank}." The aunt changed her mind and is only giving her a small amount, enough to pay off her house and car, instead. She was expecting multiple millions.
As disinterested parties, we find that very funny. Sadly, those who think they deserve all the aunt's money are now tying things up in court. That means the people who should really inherit it will get less after the legal fees and much delayed, as well. We don't have a dog in that hunt so it's no skin off our back either way.
This is the same sister who told her mom, back in 1999, that her mom should go ahead and put mom's house in sister's name. That way, when the nation imploded from the year 99 bug, sister in California could sell the property in WV. After all, with the country fallen apart, she wouldn't be able to get back to the homestead to do that. Her mom's response was "How stupid does she think I am?" along with "No."