She should be fine, but yes on newer kindles like the Scribe (came out in 2022 so not exactly brand-new now) they removed the "mass storage mode" (= what made kindles show up on a pc as a usb drive).

Calibre can work with the newer MTP mode (which is similar to what android phones have) but it's a lot less reliable and requires that no other app, including the OS, file manager, is accessing the device at the same time. It's frustrating and I'm very happy to have jailbroken it, now I can use SFTP to browse the folders much more speedily.