I have forgotten how to import a photo attached to a gmail.
If you are talking about importing the photo into your Organizer catalog, I would save the photo to the computer hard drive and import (from files and folders) from that location. If you save the photo to a Watched Folder, the image will be imported automatically into your catalog.
Photos from phones sent with WhatsApp (and other apps) have a proprietary format that is not recongized by Elements and won't be imported into the Organizer. You need to open them in a less picky program (such as the Windows Photo app) and do a Save As. This will put the image into the correct format. I think you can also use the Elements Editor to open the file with the File>Open as Camera Raw command. When you then save the file, it will be recognized by the Organizer.
Thanks very much. You have been really helpful.
I have followed your advice but the suggested solution did not ultimately work. Although I moved the images in question to Windows Photos, some would not transfer to Photoshop Elements. When I attempted to do so, I received the following message: "Could not complete your request because a Sofn, DQT, or DHT, JPEG marker is missing before a JPEG SOS marker."