Set up family group using non Apple systems

Family Sharing can only be set up from an Apple device. (Except for Apple Music on Android)

Setup Family Sharing the normal way from an Apple device, and invite users to the Family Sharing group(device the use is not important for this).

Android and Windows users can then log in with their own account at https://tv.apple.com or onto the Apple TV app on supported TVs, streaming devices, games consoles etc... and have access to the shared Apple TV subscription.

Windows users can also download the TV App preview version from the Microsoft Store and log in with their own Apple ID there, and the shared subscription should be available to them.

This is a highly complex and debatable topic. e,g, How do I setup family sharing from androi… - Apple Community

To access and manage the entire suite of things that can be done with Family Sharing requires the person who set it up must do so on Apple equipment. To learn how to set up Family Sharing, read this support article --> Set up Family Sharing - Apple Support

- Only lists doing this on an iPhone, iPad, iPod touch and Mac.

That will produce a bunch of replies saying flat outright you need to do that on Apple equipment.

However, from there we enter into what can and cannot be done using non-Apple equipment, or a mixture of both.

Apple itself has an article saying a family sharing group can be set up on an Android. Use Family Sharing with Apple Music on Android - Apple Support

"How to start and manage your own family group

When you get an Apple Music family subscription, you can start and manage a family group to share your subscription."

Now admittedly the interface will likely not offer the same extent of features that an Apple deivice may have but as the first link I provided at the top discusses, what may or may not be possible is as yet unexplored and certainly not documented conclusively by Apple.

It is theoretically possible to get access to AppleTV on Windows and Android with Family Sharing. The sharing would have to be set up on an Apple device (but the on-going discussion in the first link invites an attempt at proof of concept that might indicate otherwise) but once a person has access to a subscription then Apple says that you can play Apple TV on Windows and Android by using a web browser.

How to watch Apple TV+, MLS Season Pass, and more - --> How to watch Apple TV+, MLS Season Pass, and more - Apple Support

Family Sharing on Apple TV --> Family Sharing on Apple TV - Apple Support

"You can’t initiate or configure Family Sharing directly on Apple TV. It must be done on a Mac, an iOS device, or an iPadOS device. To learn more about setting up Family Sharing, see the Apple Support article Set up Family Sharing."

An Android user can get access to the features of iCloud+ through the https://icloud.com website.