They noticed they accidentally removed a 35GB folder full of media files from a very big vacation, including nature photography and some strange GoPro format files. Valuable stuff.
Are you sure the files were actually deleted? I used to work in helpdesk back in the day and would regularly get calls from users in similar situations, and 9 out of 10 times the folder wasn’t actually deleted but accidentally moved to somewhere else - Windows Explorer is dumb like that, it’s very easy to accidentally drag-drop a large folder elsewhere without any confirmation - just a flick of the wrist and you wouldn’t even notice it. On the other hand, actually deleting a large folder not only presents a confirmation dialog, it also takes a long time to delete the files - and you’d notice it very quickly (unless you were AFK).
So I’d recommend running a thorough search first - both on the old drive and new drive.
But if the files were actually deleted, I also second the recommendation of Recuva - IMO it just works better on NTFS drives, compared to Phtotorec. After all, if the photos are really that valuable then you really should be using the best tools available at your disposal.