if your sister’s by your server in-person, maybe you could guide them to graphically install something like Rustdesk (edit: graphical remote access, wayland isn’t well supported so make sure it’s running over Xorg), give you the access code & have them manually accept the connection so you can get back in.
You’ll be stuck streaming your terminal window and sending laggy keystrokes though whatever connection you have now (until you can get ssh running), but it’s better than nothing.
I’ve acknowledged that, while convenient, my (small) setup is still a burden that I would be asking someone to take. If your friends don’t already share your passion or knowledge for Linux/Docker/the intricacies of <whatever you may be running>, I doubt they’d be willing to take on what you leave them.
My friends had a family member who had a giant setup of Raspberry Pi’s that did Pi-hole, Home Assistant, F@H, among many other services and machines (there were like 6 Pi s!). They passed some time ago, and there’s just no one in the family who was willing to take on the responsibility to learn how to manage everything that was going on—services have been slowly degrading/going down since then.
Those who rely on your services will just go back to using Google Drive, watch-anime-free.org.ru, and pressing “Open LAN world” in the Minecraft client. I don’t think it’s okay, but if you’re out of the game, you won’t be there to object.
That is to say, if you DO have friends that are knowing and willing, you need to leave plenty of good documentation. I haven’t been one to write much of anything, and I’ve already fucked up my shell profiles again because of no documentation, but I can give some general pointers:
Basically, leave meaningful comments that explain why something is the way that it is. You should be able to use this documentation yourself as reference material. Keep this documentation updated regularly, as frequently quoted “bad documentation is worse than no documentation” (or something like that)
(sorry if this last section in particular doesn’t make much sense, I haven’t slept in $hours. feel free to ask for clarification!)