Unused email account

I received a text message from xfinity:

"Important update from Xfinity: You have a Comcast.net email account that you have not used in 2+ years, so it will be closed in about six weeks. See your options: https://t.xfinity.com/emailactivity"

But I can't figure out which email it is talking about. I went online to check, but it makes me log in with an email address. So of course that is one I'm using. I looked for a place to see all the email addresses associated with my account. Eventually I was able to coax it to tell me two, both mine. But I know there are at least a couple more associated with my daughter, and maybe more. As the person who pays the bill for this account I should be able to see them all. How?

Then I tried to chat with support about it. It connected me to a chatbot that is incredibly unhelpful. I kept asking to to connect me to a person. It kept telling me that it would, but only after I answered some other questions. There seems no way out of this that actually leads to a person.