Her PC is also 13+ years old (an old Dell Optiplex 9020), which is unsuitable for running any supported versions of Windows. The high -performance, efficient and low-memory-usage nature of Linux makes it possible for her to complete productivity tasks even on such old hardware.
There are also non-nerds benefiting from Linux on low-end gaming devices such as the Steam Deck, or the countless number of emulators such as the Anbernic RG35XX Series, Miyoo Mini etc. Linux is the reason that such humble hardware is feasible for gaming.
Yet somehow this same logic somehow becomes invalid when any open source software made by Google is brought up.
If Linux was targeted for mobile devices, there would inevitably be wasted effort reinventing the wheel just to match the feature set of Android when there’s already a suitable base to start community work from.