>I checked the listserv-logs and there is no message sent to her.


As you described this, this is NOT a problem in her RECEIVING email, but a problem in what is LISTSERV-generated to her.

I think it would be of value for you to show us all of the list definition keywords along with all of the output (not just the editted options) of the command

Q listname FOR subscriber

(removing userid for her). 

/Pete