iPad keeps asking for previous owner's AppleID
I gave my mom my old iPad when I got a new one. I had erased it back to factory settings, then installed the apps I knew she would be using. I logged out of FindMy and iCloud on her device. She is logged in and can download new apps with her AppleID. When she tries to update any of the apps that I preloaded, it asks for my credentials. We deleted the app and downloaded it again but it asked for my AppleID. I had her signout of iCloud and back in with her credentials. I verified the device is not linked to my AppleID. Why does it keep asking her for my credentials?
iPad Air 2 Wi-Fi