> She doesn't use multiple IDs. But... trying to sign into her old account...
Sounds like more than one. She needs to quit using the phone with "old" IDs, she's confusing herself and the device.
Get logged into https://appleid.apple.com/ and get it sorted out there. If you can't log into that, get on phone with Apple support until you can. As long as you didn't two step auth it, the phone support can and will help.
I'm not trying to debate, btw, I'm trying to legitimately help. Like most of us here, we end up being the support person for our family's devices, and I have seen people get themselves in a jam w/ the ID before. Clearly defining the Primary Apple ID won't be resolved until it's clearly resolved in the web interface.
Sounds like more than one. She needs to quit using the phone with "old" IDs, she's confusing herself and the device.
Get logged into https://appleid.apple.com/ and get it sorted out there. If you can't log into that, get on phone with Apple support until you can. As long as you didn't two step auth it, the phone support can and will help.
I'm not trying to debate, btw, I'm trying to legitimately help. Like most of us here, we end up being the support person for our family's devices, and I have seen people get themselves in a jam w/ the ID before. Clearly defining the Primary Apple ID won't be resolved until it's clearly resolved in the web interface.