Help - Syncing between devices

Hi, within our household my two young daughters share my iCloud account on their iPads. Some time ago I believed I set them up so that they couldn’t view any photos, albums on my iPhone. My daughter announced this morning she can see all my photos. Where there’s nothing inappropriate I do take various screenshots of gift ideas, family bookings, etc. Devastated that she’s seen various surprises prior to Christmas period and I need to quickly stop sharing across the devices. I’ve de-selected the toggle on photo steam but what else do I need to do? I deleted photos from her device which in turn are now deleted on my iPhone of which I want to restore. If I do this will they go back on her device? I had recently had a health check on both iPads at our local Apple store and wonder whether this viewing of my photos has just started when we did a reset? Please could I have advice for what I need to do on iPad and my iPhone. Thank you so much.