I was about to write 'barmaid' when I remembered maids of any kind are thin on the ground hereabouts, even thinner by the time they're old enough to pull a pint.
I appreciate it's a generic term that doesn't preclude intersexuals and those who simply (in the memorable words of one entrapped high court judge) 'enjoy the freedom only a skirt can give' but bar girl came out unbidden. Either way folk is off the menu and drinkers can enjoy their ale without being troubled by invitations to repeat a chorus.