I know I wouldn't care because I'd be dead, but I really do not want my family getting on to my personal devices after I'm dead. Those are things that I will never give them the passwords for, not everything is their business.
My parents simply made a list of passwords on a piece of paper, buried with the other important papers.
i have all the family photos on encrypted devices, and the most efficient way to share them is to share the passwords for those devices. my phone they don't need because the important stuff from the phone is backed up anyways, so they just need that backup.
so i guess the easiest way is to keep separate backups of stuff you want to keep private and stuff you want to share.
Especially important to communicate that in your case, on the off chance they want to hire a data recovery firm in some hope of saving wedding photos or something
I share any photos with them they might want, but I hopeful that Apple's security setup prevents any practical data recovery. I know my family too well, if I explicitly said "this is private" they'd be trying to get in the moment I was cold.
There's nothing bad on my devices, but there's lots they don't need to know about me.
Both devices are encrypted, and the samsung I believe is set to wipe after a number of failed attempts. While there probably isn't anything on them, it's always been a pain to not know.