Who is the Serjeant-at-Arms? How many female Serjeants-at-Arms have there been?
The Serjeant-at-Arms carrying the Mace.

DPS Auspic
Description
The Serjeant-at-Arms carrying the Mace in the House of Representatives. Behind her is the Speaker of the House of Representatives.
Permission should be sought from DPS AUSPIC for third-party or commercial uses of this image. To contact DPS AUSPIC email: auspic@aph.gov.au or phone: 02 6277 3342.
The Serjeant-at-Arms is a senior officer in the House of Representatives. They assist the House to do its work. This includes maintaining order in the public galleries and delivering messages from the House of Representatives to the Senate.
The Sergeant-at-Arms is also one of the few people, other than members of the House of Representatives, who work in the House of Representatives.
There have been 6 female Serjeants-at-Arms in the Australian Parliament.