No Email

@XfinityMartyR​ 
XfinityMartyR, thanks for answering.  We got it working yesterday, I'm glad to say!  
Yesterday's "adventure" started with a visit to the local Xfinity store front, staffed by Xfinity-branded partners, i.e., non-employee vendors (sigh, so much has changed since she retired in '07, and I stopped working for Warner Cable in 1990).  We got a helpful gentleman at the store (we didn't expect a helpful anybody there...SURPRISE!) who gave us a number to call a real person.  So we went home, called the number, and found out there is a section that deals with email-only problems.  

Long story short, what I did at the password link you suggested above was follow the directions "Enter your Xfinity ID, email, mobile or username".  I entered her username and got the "Connect to your home Wi-Fi to reset your password".  What seemed to fix the problem (I think) was instead of just entering the username, I ended up entering her ENTIRE EMAIL ADDRESS, i.e., username@comcast.net.  After going thru all that was involved in setting up a new password, all the missing emails poured in.  

Many thanks to the nice, patient lady who helped us, even though it was difficult understanding her through her accent.  But something tells me that her English is still better than my ability to speak ANY foreign languages.  I'm 75, with a background in cable tv, electronics and customer service, but I still can work thru this stuff when I have to.  Imagine how difficult it is for people without the required mental or technical acuity or patience needed.  How hard it must be.

Thanks again!

@w9jbl​ 
I see they (the Xfinity algorithm or some other non-human) edited what I think was the solution, which was enter the entire email address

@w9jbl Thanks for getting back to us and letting us know your issue has been resolved. We are real people and do go back and edit out personal information to protect our customers. :-) Please let us know if anything comes up!