Setting up BTC fund for family member

I have been holding BTC through self custody for a few years now with my cold wallet, so I'm familiar with how to set that up, securing seeds, etc.

I have a very close relative that is interested in creating a BTC fund for the next generation but is most likely not a good candidate for self custody. We've so far started off very small over the last couple months but interested in making some more serious moves here soon. I am mostly responsible for setting this up and securing it, but this relative will be able to get access to seeds if something unexpected were to happen to me. I have discussed what to do in the event that this were to occur and wrote an essay explaining how to restore funds through seeds, how wallets work, what not to do with seeds, etc.

I've set up a single sig wallet w/o a passphrase. I thought about the idea of getting into multisig, but after a bit of reflection I felt keeping this as simple as possible while putting more effort into securing the seeds was a much better option. Therefore, I stuck with a standard single sig wallet to avoid overcomplicating the initial setup and eventual recovery/restoration of funds once the wallet device itself becomes bricked lol.

My biggest fear is somehow losing these funds because of stupidity or user error. I've devised a plan with regards to securing seed phrases by having backups and not keeping them all in one location.

I'm looking for some input/advice on this. Purely looking at holding BTC for DECADES and not fooling around with Defi and other crap that you connect your wallet to