Photos being shared between apple IDs on family sharing

I recently change my apple ID on my iPad to my own (as it had previously been my mother's), and as a result my photos seem to be getting messed up on all of my devices. I am now getting a bunch of my mother's photos on both my iPad and my iPhone despite triple checking on all my devices that I am using my own apple ID. This has never happened before and I am really confused as to why suddenly I am getting her albums and photos when I thought that you could only share photos to other apple IDs via family sharing if you added them to a shared album (which neither of us have).

Thank you for your assistance,