Focus on services before devices. iCloud to Nextcloud, iPhoto to Immich, HomeKit to Home Assistant, etc. You can start using them concurrently, alongside Apple services so you still have that safety net while you figure things out. Most self-hosted services will have iOS/MacOS/TVOS clients so you can start using them now. Then when you’re ready to swap a device, you’re mostly ready to go.

I’ve been working on this myself after being all in on the Apple ecosystem since 2006. So far, I’ve moved to Jellyfin for my media, and made the Nexcloud and Immich switches. The most important thing here is that as you start to self host more important things like photos and documents, have a good way to back up that data.

So I’ve been working through this myself recently. I was pretty deep into the ecosystem and frankly there’s not a replacement for everything, but most of it’s close enough for me. Much of this will depend on what you’re really wanting to accomplish.

For Mac you didn’t mention whether it’s an Apple Silicon or Intel device, so this is going to all be specific to my experience which is with Asahi Fedora Remix on an M1 MacBook:
I use the GNOME version since I think the UX has some Apple familiarity and works well for laptops but Plasma is probably a better choice for a desktop.
It’s generally very stable but it doesn’t really have anything yet to easily translate x64 apps to ARM - there’s muvm, but if what you’re trying to run isn’t covered by the included libraries (e.g. Electron apps) you’re going to have to build an overlay filesystem image containing the dependencies you need; it doesn’t “just work” like Rosetta (or in the Windows world, Prism).
You will also lose some of the stuff like Touch ID because reverse engineering the SEP and sepOS are still in progress. Battery life also isn’t as good.
Lastly, Linux desktop security simply isn’t comparable to any modern build of macOS. TCC on macOS provides incredibly robust protections for user data and device access that Windows and Linux simply don’t offer (yet). On the bright side with Asahi, you do still get some decent protection against low-level compromise because each OS (“container”) on Apple Silicon has its own verified boot chain and recoveryOS, which is largely immutable, can in theory be used to nuke an infected install.

I replaced my iPhone with a Graphene Pixel, but I mostly just use it for web browsing and email and I was an Android user for a long time prior so I can’t speak to whether this would be an easy transition or not.

My replacements for Apple services so far are:

• iCloud Drive: Nextcloud with a Managed Service Provider with Cryptomator to approximate the end-to-end encryption offered by the Advanced Data Protection option.
• iCloud Private Relay: Mullvad, though any trustworthy VPN should do. Note that it’s not an exact replacement because iCloud Private Relay traffic originates from Apple IP ranges which tend to have a much better reputation than VPNs and thus run into anti-bot measures less frequently.
• iCloud Mail, Calendar, Contacts: Tuta mail + Addy.io for the “Hide my Email” aliasing component.
• iCloud Keychain: Proton Pass, though whether you’d want to trust Proton at this point is another topic of discussion that’s out of scope here.
• iCloud Photos: I’ve recently tried out Zeitkapsl and have been extremely pleased with it. Their desktop app originally didn’t have an ARM Linux build so I reached out to see if one might eventually happen and within a day or two their team had one ready.
• iCloud Notes: This one is tough to replicate. It’s so simple, yet it’s probably one of the most valuable products for me in the ENTIRE Apple ecosystem and one of the few utilities I actually found value in having synced between all my devices. I’ve been using Obsidian with the .md files synced in a Cryptomator vault to replace it, though I may end up subscribing to their sync service just for ease-of-use.

There are other viable options for most or all of these; I had a pretty specific set of requirements in mind when making my choices: no documented data collection or sharing beyond what’s absolutely strictly necessary, no Google analytics or push notifications, European owned and hosted, end-to-end encrypted where possible, no advertising, no profiling, etc.

If you have any questions let me know, hope this helps though!

I’m the one who migrated off macOS, but I’m still heavily on iOS. All of my family is with iPhones, and we have a bunch of iPads. I’m having MacBooks, and they all run Linux (they’re old Intel models, and work perfectly well on Linux). Our home computer is on Fedora too.

As for the migration, I’d suggest making an attempt at migration with some old laptop: ThinkPad or even older Intel MacBook, the Retina 2012…2015 line up works really well for me. That way she’d have an opportunity to slowly learn and compare.

Apple’s ecosystem wasn’t bad when I migrated, and I was somewhat scared to switch fully. I did that only when I realised I haven’t touched my macOS MacBook for years! (We’ve been watching TV series off it, to keep the battery functioning more or so.)

Also, what helped is me realising I don’t need that tight integration between the phone / tablet and laptop / desktop. They’re different devices: to consume content vs to create it. So, it helped. But, I’m still learning the new apps. Particularly the design ones are awful on Linux. Figma is mostly the same, but Inkscape is just miserable, but I’m trying to keep using it, even despite the interface being terrible. Gimp turned out to be okay, more or so. Krita was mostly good too, so I don’t miss Photoshop. But I do miss video editing software. I hope Blender might help some things I miss, but I’m yet to learn it.

Interface wise, I think Gnome is perfectly fine for a macOS refugee (just search for the solution to keep cmd + v behaviour, there’s the project for that, I forgot the name: Toshy something; I use my own shortcuts now). However, you can make KDE behave very similar to macOS, to ease the transition.

The primary pain point is the apps. They’re different, and usually worse. Sometimes they’re better, if you strive for simplicity. So, it’s a mixed bag. Myself, I don’t see myself going back. I may use a MacBook with macOS, but my primary system at home would be Linux. As I have too many tiny little things now that are Linux exclusive.

Pushing someone, even gently, to change something about their routines almost always causes them to become defensive and double down. The most effective way to enact change in someone else is to discuss how the changes you’ve made have benefited yourself.

I’d start with a cell phone first. The last thing you want to do is give up your life to google and microsoft. Get yourself a graphemeOS compatible phone and replace all the apps with open source solutions. There is a (very very brand new) app called Vela Maps that acts just like google maps, only you can choose not to talk to google servers when you do.

Use sync-thing to auto upload photos to a server you control, even her home PC

There are ways to change the linux desktop to look like apple, though I don’t know what they are. possibly KDE?

unfortunately only google pixel tablets work with grapheme OS. There are tablets that are compatible with ubuntu touch

As for the watches, I don’t know of any that are de-googled.

A relative of mine attempted to move from an iphone to an android phone, and generally move to other services on non-apple patforms. Not really self hosted, but I tried to help a bit in that area too, placing them on some of the things I run. The reason was their own, they saw pictures taken by a friend who had a flagship android phone and thought the pictures were amazing in comparison and wanted to try it. They were not even that deeply into the ecosystem, didn’t have watches or anything, just the cloud services.

Sadly what happened was that apple makes you feel so cozy and content in their UI design that anything even slightly different is really disruptive. It didn’t go well, and the experiment lasted about 6 months and then they were back on an iphone again. I would hear constant complaints and cursing about various UI differences. Touching parts of the screen triggered actions they weren’t expecting, and they couldn’t manage to learn the new workflows. It was sad to watch, and I hope things go better for you. In my opinion Apple is really good at attracting people and slowly convincing them that they don’t have to think for themselves anymore, so then when they try, they no longer feel competent enough to do so.

A clear purpose and clear expectations help. It’s important to remember why using Linux is valuable. It’s what keeps us pushing through, even when it gets tough. It also helps to know that not everything will work right out of the box. And, to an extent, one can assume that that is the cost of using Linux.

One thing that inspires me is Snowden’s quote that says something like “We won’t win with features, but with ethical convictions”.

Now, as to what steps to take, focus on safe-to-fail experiments. Start by making relatively small changes, even within the Apple ecosystem:

• Safari to Firefox
• Pages / Word / Numbers / Excel to LibreOffice
• Photos to Ente or whatever you want to use

Once these changes are part of daily life, you can attempt a transition to Linux.

The idea here is to make change sustainable.