I'll hazard a guess at who that was...
YGM, with the email address of the EDI airport manager for BD/LH, should you wish to bring her behaviour to his attention.
Her response was unacceptable; on the other hand, the check-in agent was also wrong. The lounge doesn't open officially until 5.30am, but it is often open before that if the staff are in early
Did you have a good time in EDI?