Linux

Mint is based on Ubuntu but not made by Canonical. Dint worry about it.

Don't listen to fearmongers and keep on doing what you doing.

I think you chose well with Mint. It is based on Ubuntu, but has a track record of stripping out Canonical's nonsense, and if said nonsense should ever become impractical to remove, Mint already has a contingency plan in the form of their Debian Edition.

Someone said that LMDE is behind in various ways,

Someone on social media is always echoing the meme about Debian being unusable due to old packages, but roughly 96% of the time, that person turns out to be poorly informed and driven by an unhealthy addiction to quickly rising version numbers. Try not to give their opinion much weight, despite how loud and repetitive they are.

including NVIDIA graphics drivers

Why would "non-tech-savvy seniors" care what version of the Nvidia driver is installed?

Edit: To answer the question in your headline, putting the /home directory on a separate partition tends to make switching distros easy.

The Mint team removes the bs Canonical puts in Ubuntu - that's why they're the best beginner distro - it'll be fine.

I'm not 100% sure on how things work, but if Ubuntu does get ads on its desktop at one point, I'm almost certain that it won't propagate to Mint.

regardless if you switch distros or not it's good practice to backup stuff to either a personal server or even a private git repo.

I distro hop every so often, heck just did it lastnight, and what makes it easy for me is using borg which backs up daily to my server. It backups personal files, ssh stuff, and some dotfiles. I also do a push to my private forgejo before hopping and that will be configs and what have you so when I'm on a new distro it's just a matter of cloning that private repo and then accessing a recent borg backup and i'm good to go. For Arch based distros I use something called DCLI which backs up a list of packages I have installed so I can pull that down and then merge it to my system and it automatically installs the packages I want. All of this allows me from once spending a couple hours setting up a system to now a few minutes. Doing all this makes distro hoping a non factor for me.

it's not that deep bro

What do you mean by the easiest way? For me, that’s pretty simple: backups. In general, it’s a nice idea to have your /home separated (partition or disk), but in reality, I don’t bother. I just do backups. Considering things are mostly in the cloud (e.g. browser bookmarks), the backups are usually just the files, rarely some configs. That’s why I don’t bother separating home even for myself. Most times reinstalling something is not an issue. Actually, rather teaching someone using the interface is more of a problem.

That’s why I wanted to ask why did you choose Mint for your task? I’m trying to migrate one place to Linux off Windows, all they do is basically browser and some printing (I checked, their printer works out of the box with Linux). I settled with Fedora atomic desktop. First I wanted Kinoite, as KDE is very similar to Windows, visually. But I gave it some thought and realised it’s too complicated for a basic use case, and Gnome is just very good and simple, and perhaps it would be just not too difficult to have them learned the new interface. It’s not much after all: the top left corner, plus top right corner to power off the machine. I expect them to get familiar in no time, but I’ll see how it goes over time, as I have just installed the whole thing very recently and haven’t migrated them fully yet. (I have to transfer their files to the new SSD I bought them, before giving them the new system.)

I thought of Mint myself, but I don’t like Ubuntu, never liked Mint, and I thought I’d prefer something more modern. I just have very positive, mostly positive, experience with having Fedora at home, it was mostly great for years, with some occasional inconveniences. But since I’m pretty experienced with Linux, most things could be fixed within minutes. I’m yet to discover how it would work in the wild.

It depends.

If it's your own sister, then you learn to deal with her. If anything, adding a sister is fine as long as you have the resources. Removing a sister has legal proceedings upfront or after the fact, depending on your method.

Switching between romantic partners who happen to be sisters with each other can be risky! Lingering affection, jealousy, and inadequacy may all come into play here.

Personally, I dated one sister only to find that the younger one fancied me after well after we broke up. I found it difficult to separate the relationships and never pursued it. My brother-in-law dated my other sister-in-law first, and moved to his wife after a mutual understanding.

Finally, romantic entanglements with your own sister is discouraged. Not only is it illegal in many countries, having a child with your sister invites genetic disorders.