I set up a Dead Man's Switch. It sends me an email with a link every day. If I click it, I acknowledge that I am alive and nothing happens. If I do not, after a grace period and more reminders, it sends an email to my wife with a password-protected file. I have listed all our accounts, passwords, assets, etc., along with instructions on what to do and whom to ask for help.
Disclaimer: I sell digital legacy products. However, I also honestly use them, and some of these tools I distribute for free and have made open-source.
Wow, that contains a fatal weakness (no pun intended), that She won't assume the email is spam (or a scam) and just delete it without opening it.
It's quite possible for you (or anyone who uses your work) to have the outcome they were trying to prevent because of this.
She knows about it, so she will actually be expecting it.
But yes, that is indeed a risk, particularly for other family members who don't know there is an email for them.
Wow, why every day and not weekly? Every day seems too frequent.
I also thought that, but I like it this way. It supports weekly checks as well.