There were a number of exciting announcements from Apple at WWDC 2024, from macOS Sequoia to Apple Intelligence. However, a subtle addition to Xcode 16 — the development environment for Apple platforms, like iOS and macOS — is a feature called Predictive Code Completion. Unfortunately, if you bought into Apple's claim that 8GB of unified memory was enough for base-model Apple silicon Macs, you won't be able to use it. There's a memory requirement for Predictive Code Completion in Xcode 16, and it's the closest thing we'll get from Apple to an admission that 8GB of memory isn't really enough for a new Mac in 2024.
That all depends on how much work they want to put into troubleshooting it for her. I got my mom a Mac Mini when her PC needed to be replaced. It’s way less responsibility on my part. I mostly just answer the occasional how-to.
Mac is easier than Windows, sure, but not easier than a chromebook. Nothing is simpler than a Chromebook. You can do much more with a Mac, but a chromebook is much easier.