I am in the same situation as you, Bimmerbill.
In my case, my will has my estate going into a testamentary trust (i.e., created by my will) for my three kids. My sister is the trustee, and has latitude to pay for whatever expenses she approves of from the trust while they are minors. The kids get 1/3 of their portion of the trust at age 30, 35, and 40.
It's not complicated; all the stuff for the trust is directly in my will. My attorney treated it as all very run-of-the-mill stuff.
FYI, in my state, there is a specific state law that says if you're divorced, your ex is treated as pre-deceasing you for the purposes of interpreting your will. I dunno if your state has a similar provision.
"At times the world can seem an unfriendly and sinister place, but believe us when we say there is much more good in it than bad. All you have to do is look hard enough, and what might seem to be a series of unfortunate events, may in fact be the first steps of a journey." Violet Baudelaire.