Simply makes /who on character who whispers you and repeats it after at least 120 seconds if there was no more whisper. (Change this number in .lua file if your want more/less).
Stores 10 characters. Replaces the the oldest one if new character whispers.
Resets all on reload/login.
Works on both classic/bfa, cause of simple code.
Only tested with standard Blizzard chat frame.
There is a time limit on /who command, so do not wonder if it fails to show result on simultaneous whispers.