Move Photos from one Apple ID/iCloud to another
My mother recently passed away. She had about 2000 photos from the last 10 years that she stored in the Photos app and backed up to her iCloud under her Apple ID. As I prepare to shutdown her iPhone and Apple account, I would like to move those photos to an album or library under my own Apple ID. In that way, I hope to then have a shared album or library that I can share with my sister, so we can go through all her photos on our own schedule.
I have already exported all the photos to a backup drive for safe keeping, but in doing so, there turned out to be multiple duplicate file names that were overwritten or skipped. Hence, I would really like to be able to copy/move her library as is within Apple's ecosystem to Photos / iCloud under my account.
Thanks for any help.