Linux

I would highly highly highly recommend a atomic distro. It's going to be a much nicer sandbox for someone starting out, regardless of age.

I'd go raspberry pi for kids - gpio projects are fun and linking computer to physical world.
The newer ones are a bit pricey for what they are though.

What does your wife have against linux? All the porn pop up viruses are on windows, and getting your kid on apple is setting them up to be in credit card debt for the rest of their lives.

Even my senile ass grandparents use Linux and they don't complain about every little thing like they did with windows. My dad wanted a Mac but free so after hackintosh being too much learning curve for him I used some random Mac inspired configs from the internet for one of the Linux DEs that I've never personally used, also no more babysitting and virus induced full wipes.

Parental controls I would do at the router level because eventually kids will surpass you in computer skills. Or maybe they won't because of seo and ai articles taking over the web.

Don't overthink this, it's a kid. She/He would not be yet biased like you or your surroundings. About wife - I don't she would be against teaching kid how a computer works, maybe you explained it so she heard "hey can our kid spend more time in front of a screen and with my geeky thing" :D.

I have a little smart sister (now 9 yo) that use Linux, it started with her making a mess on Windows login (parents laptop) so I asked if she wants "her own space", but instead of new account I installed whole Fedora on second partition. Why Fedora? Because It works and looks nice, there really is no need for "educational", just install education programs on top.
There are basic parental controls in vanilla Fedora, but honestly there turned out to not be needed, she don't hook too much after first shock of tech and like two cries she learned to stop when we say to stop, at least most of the time. Depends on the child, I suppose some really need a timer, that's up go you, nothing bad with that. I have showed her some games too, she loves everything Tux. I teach her how computer works this way, showing more and more programs with time and every new icon of Krita, GCompris, Goxel or Scratch is new great thing. She has Windows at school, but everything works on her space too. Well almost, LibreOffice does not has 'online cliparts', so instead of arguing with 9 year old I told that program at she uses at school is not available on this OS (after a while of teaching she knows OS is something something wow the desktop looks like :D) and showed how to download search copy from the browser. With being honest and just responding on every little childlish curiosity question she already knows more about computers than her mother. I just made it normal for her, as after using Linux for years it is normal for me.

When i was 9 my sister gave me a laptop she put ubuntu on and it pretty much worked for me. I have a pretty good sense for computers and maths so that probably helped. And on another note, no i didnt get trauma from unrestricted access to the internet because i never searched for stuff like that. The first time I started seeing(and thus avoiding) gore/shock videos was when my classmates also got devices. I think if you teach your kid well they will learn to avoid these things but be carefull because other parents(especially today) dont teach their kids about safety. Your milage may vary, im not a parent.

My wife is not a fan of the idea, however .

Divorce!

Jokes aside, Edubuntu should cover you parental controls and Education tools needs. And since it comes with Gnome by default the UI should comfortable to your children. I suggest diving into it if you need more something sprecific. Good luck!

PS: There are some good articles flying around about how to convert your loved ones to linux. I have one measly convert and my advice is to show them how can linux solve their problems.

I got my daughter a surface book with Archlinux on it when she turned four. She'd previously been using an ipad so I wanted something that had a touchscreen, and I installed KDE as the desktop. She learned how to use it extremely quickly, and has even started in on the commandline now that she's 5 and knows how to read. GCompris is great too.

Me and my wife haven't bothered with parental controls and instead just keep an eye on her usage, but I agree with other commenters that controlling things at the router level seems like a better bet.

Don't put parental controls on it. What do you want to control? Maybe put controls on the website that they can visit, but that goes on the DNS or router. Most kids will go to a mate's house that doesn't have any or as harsh parental controls anyway if they are particularly keen on seeing something that they 'shouldn't'. Parental controls are a fix for parents who can't talk to their kids; they make the parents feel safer but just send the issues underground. Gen X will have been writing code for a while at your child's age. I was. There was no choice if you needed to unlock a game you could've afford. At that time GUIs were a bad overlay over MS-DOS or DR-DOS. You had to know what you were doing to get the best out of it. Your kid will be fine with any distribution of Linux. If your kid is technically inquisitive likely to be good at maths/science, get them installing Arch. If not and they just want to use a browser, install one of the top five popular distributions from distrowatch.com. The Office suite for Linux is called LibreOffice. If you use Chrome as your browser you'll easily tell if your child has been on bad sites because your timeline will be filled with adverts for unsavoury impotence remedies. Enjoy.

PS printers are still bastards in Linux. Happily they're less bastardish in Linux (and Mac, because Linux and iOS use the same printing software) than Windows. If you like your life buy a decent Laser from anyone but HP - my generation bought the last decent HP printers they made.

My kids, 9 and 11, use OpenSUSE Tumbleweed. Mainly because that's what I use. They were with me when I set it up to choose a name for the computer, a username and a password (for their user and for the disc encryption).

I showed them how to configure wobbly windows (most important part) and how to use Discover to install games.

I installed Minecraft. I installed Steam (which has its own parental controls). I configured emails, Nextcloud and a password manager. I configured automatic updates.

I think that's about it.

They're responsible. They ask me for help if they need some. We educate them about people they meet online in Minecraft and other games. Works well so far.

Every distro is essentially the same it's not the question you want to be asking

I'd probably give them Linux Mint.

Voilá: https://www.spacefun.ch/icefun

Any normal distro. Kids learn fast. No one taught me how to use Windows 95, or XP. We figured it out.

Arch linux? :) joke aside perhaps something with btrfs support is handy. you can easily rollback if something breaks. For parental control don't give the kid sudo/root. other then that restricting websites and stuff is more easily done on a firewall outside of the kid its control.

Almost any of the larger distros will suffice i think. Personally a fan of opensuse tumbleweed which has btrfs support out of the box. use a DE like kde/gnome and i think you have a very solid start

What do you think Hannah Montana Linux is for?

When I was a kid I remember being confused at what the installation questions were.

If I were my own parent, I’d explain how the OS can sort itself (FHS, Windows, macOS). This gives confidence for installing and inspecting software.

Next, I’d explain how drives work and how they’re represented in different systems. That means partitions and formatting too.

That would then take me to explaining what’s involved in OS installs, erasing everything, dual booting, retaining personal files, etc.

My kid, believe it or not, uses a NixOS laptop regularly. He doesn't configure it yet, but honestly I'm not afraid of him having a go. When I was just about his age, I was figuring out DOS without the Internet to help, and while it was orders of a magnitude simpler, the documentation was orders of a magnitude more sparse too. Any of the big, well-documented distros (Ubuntu, Debian, NixOS (for some values of well-documented anyway), Fedora) would be fine. Honestly, I'd even let him loose with Arch at this point, or even Linux From Scratch.

DebianJr is the easiest pre-packaged distro for kids 7-12.

Under 12, I would keep it fully offline(remove NIC or blacklist MAC address.

Install a local wikipedia instance (or simple-wikipedia) for reference, and give them thumb drives/DVDs for media.

For the fully libre start to life, install Trisquel GNU/Linux and use the DebJr package list to install required software.