I can only see the last picture so take what I say with a pinch of salt.
1) she’s trying to open the autosaved file. She must have another saved under a proper name (not ”17”)
2) did she try to move the file 17, like putting it on a usb key when PowerPoint was closed?
If not, can you get her to tell you what she did since she last work on the file?
Also, she needs to be careful not to continue working on that Mac for the moment as any new work saved could erase the file that will possibly need recovering.