Ever tried shotwell? https://wiki.gnome.org/Apps/Shotwell I use it under XFCE, does wonders with my Nikon camera and some old tablets.

Shotwell is unmaintained. There are two other photo applications, but it's not clear which to use. In any case when you plug a camera or phone into a GNOME desktop what happens is the file manager application and any camera programs you have installed all compete to open the camera. In my wife's case the file manager always appears to "win" and Shotwell gives an error about not being able to find a camera. IOW basic functionality, broken for years.

Rats... unmaintained. This is sad, really. About your wife problem, it might be due to a daemon being instructed by the DM to automatically mount and open any newly inserted memory card or USB devices appearing as such. I don't know about Gnome as I use XFCE, anyway on the removable media options there is one to auto mount removable media and I keep it unchecked. Their icons appear anyway on the desktop, but until I access them they don't get mounted so they remain accessible for other software. I'm sure there is such an option on Gnome too.

The problem with shotwell is that is too much greedy. After running out of space three times in a day and finding again an autogenerated shotwell cache with several Gigas of garbage, I find it more annoying than really useful.

This is strange, I never had such a problem, but in my case I don't point Shotwell to my main image directory (which is on the NAS) but to a local one where I store photos before I decide what to keep and what to ditch. Every X days/week/months, depending on laziness :), I open its directory and move most important images onto the NAS. So nothing very big, but over here it still points to a tree containing several hundred photos without hitches.

GNOME guys seriously need to learn to make land pages.

PTP?