Verified answer

When she "replies" to one of your emails, and you still don't get it---that usually means that your mail is blocking her address. This happens (accidentally) more often than you'd think.

You will need to check your blocked list and remove her address from it (if you find it there).

Mail page>>options (top right corner)>>block addresses. Find her address in the list--click on it--click "remove block".

You should have no problem now.

?? Using Beta or New mail ? Go to mail page>>options>>mail options>>spam>>block addresses.