Hello Soniccj7,
Thanks for asking the Apple Support Communities about iCloud Sync.
With a PC, this is not an option. Just stop syncing, and if the photos are not removed from their device, only then they can delete the pictures.
This is just the way iCloud Photos works with Windows as mentioned here: If your iCloud Photos aren't loading on your PC - Apple Support
"How do I download all of my photos and videos to my Windows PC?
In iCloud for Windows 11.1, optimized versions of all photos and videos automatically download to your PC once you enable iCloud Photos. Open the photo or video to download the full version.
In iCloud for Windows 10 and earlier, after you turn on iCloud Photos on all of your devices, any new photos and videos you add to your library will automatically download to your PC.* You can also download your photos and videos by year. You can find the download button by clicking iCloud in the Windows Notification Area.
* New photos and videos automatically download to your PC at C:\Users\your name\My Pictures\iCloud Photos\Downloads."
Thanks.