"I renamed the phone to her name. Could that have done it?" Yes, that could have done it. You can try to change it back using Change your Apple ID https://support.apple.com/en-us/HT202667.
But, I think you will have a problem because you would be trying to use an Apple ID that is, or was, in some way, associated with another Apple ID of yours (e.g., as a reachable at email address or a notifications email address). Note that you can't use such an Apple ID for an uncertain period has passed --sometimes reputed to be up to 30 day and sometimes 1 year. Also, I have seen that you never can use such an email address again (e.g., if the account was deleted). But, you can contact Apple support using the options below to check out the currently quoted wait period. Also, if you need to use a new Apple ID now, then you can create a new one, although, unless you reset your device to factory fresh, it will not be the Apple ID shown on your device. See How to create a new Apple ID https://support.apple.com/en-us/HT204316.
Apple telephone support https://getsupport.apple.com/caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362
Be patient. Sometimes Apple phone support is not available.
Apple ID Support https://support.apple.com/apple-id
Apple Support Twitter https://twitter.com/AppleSupport There may be an hour or so wait.
Apple ID account security for country-specific and region-specific help https://support.apple.com/en-us/HT204169
Get Support: We’re here to help https://getsupport.apple.com/. Go through the options to find the best support option for you.