Also, if the system isn't shut down cleanly, it will never just boot up again in spite of supposedly using a journaling file system. She always has to run e2fsck in manual mode (i.e confirming every single repair), specifying the address of a backup superblock.
Printing and scanning is broken as well. Not for some niche hardware but for one of the most widely deployed HP printer/scanners.
So on her particular laptop, Linux is anything but plug and play. If you're saying that Linux works well on your laptop I will believe you. It has never worked well an any laptop I owned and drivers have always been the main reason for that.
I believe you cannot simply run Linux any laptop. You have to buy a laptop specifically for Linux.