Enlisted in the the Australian Regular Army on 20 September 1994.

After completing training at the 1st Recruit Training Battalion Kapooka, she was allocated to the Royal Australian Corps of Transport.  On completion of Initial Employment Training (IET) at Puckapunyal as an Operator Movement (OPMOV), she was allocated a position with the Movement stream.

Throughout 18 years of service, she progressed through the ranks from Private to Warrant Officer Class Two. Her postings/positions within the Movements Trade and external to Trade positions include:

• 1st Movement Unit, Brisbane / Joint Movement Control Office (JMCO) South QLD – Brisbane;
• JMCO Sydney – Sydney;
• 1^st Joint Movement Group (1JMOVGP) – Joint Movement Coordination Centre (JMCC) – Sydney;
• 10th Force Support Battalion (10 FSB) – Townsville;
• Headquarters 1JMOVGP – Sydney;
• Soldier Career Management Agency (SCMA) – Queenscliff;
• Army Logistics Training Centre (ALTC) – Townsville; and
• Warrant Officer and Non-Commissioned Officer Academy North Queensland (WO&NCO Academy) – Townsville.

WO2 Maddern completed the following deployments:

• Operation Tanager (East Timor), Feb-Aug 2001
• Operation Slipper (Middle East), Jun-Oct 2002
• Operation Anode, (Solomon Islands) Jul-Nov 2003
• Operation Catalyst, (Middle East) Mar-Jul 2005
• Operation Astute, (East Timor), Mar 2007
• Operation Catalyst, (Middle East), Apr-Aug 2007

She had been awarded the following:

• AASM – Australian Active Service Medal
  • with clasp East Timor
  • with clasp ICAT (International Coalition Against Terrorism)
  • with clasp Iraq 03
• AFGCAMMED – Afghanistan Campaign Medal
• IRAQCAMMED – Iraq Campaign Medal
• ASM – Australian Service Medal
  • with clasp Solomon Islands 2
• DLSM – Defence Long Service Medal with first class
• ADM – Australian Defence Medal
• UNTAET – United Nations Transitional Assistance to East Timor Medal

WO2 Maddern discharged from the Service on 24 September 2012.