I'm 69 and almost 8 years post-retirement so I'm finally starting to get comfortable with the idea of giving some of it away now. My net worth excluding the house (about $300K equity there) has increased on average by 3.6%/year since retiring, there's really not much more I want to spend it on and now I'm getting a $1,700/month bump in SS going to my own record from Survivor benefits.
In some ways my situation is simple. My son, age 37, is my only child and he and DDIL live frugally and responsibly. The marriage seems very strong. OTOH, they have a tendency to give money away- to people they know who are genuinely down on their luck and to their church (I like the church- there's no arm-twisting going on and I support my own church generously). DS loves his job and claims he wants to work till 70. No guarantees there and I've pointed that out. They're saving but I have no idea how much, with 3 small children.
So...
I put a lot in the kids' 529 accounts. It shelters the investment income from taxes and DS and DDIL can't use it for anything else.
I give them "experiences"- little things like dinner at a good (but kid-friendly) restaurant that's out of their normal budget, taking the kids for haircuts at Shear Madness, getting a hotel room when I visit so the 2 older girls can explore it and enjoy the pool. Soon, I hope, I can take the 2 older ones on 2-night plane trips to Chicago, which I did with the older one before COVID. When their little brother is older I want to take the whole family someplace- maybe Costa Rica.
Last year I did give them $18,000 and I should be able to do at least that much this year. One check was to DS and one to DDIL so neither exceeded $15,000.
Then, when DDIL's father died recently and they discussed plans for her mother to move near them (which her parents had planned before her Dad got colon cancer), DS told me that he'd told DMIL they could help her with a down payment. Ummm, I think I know where that will come from.
So... I have to accept that I cannot give with strings attached and tell them they MUST invest it in XYZ. It will probably decrease what I hand over now but when I leave this earth they should have plenty for a comfortable retirement and the kids won't have college loan debt.