The service offers 24-hour support and aims to reach urgent cases within 45 minutes of receiving a referral.
"If someone's on leave it leaves us short. We would like to add another five this year."
Last year 593 Wairarapa people received help from Victim Support.
Mrs Zittersteijn, who was a volunteer before taking up her role as co-ordinator, said working as a Victim Support volunteer was rewarding.
"There's a lot of satisfaction in helping people and being part of the community - being able to help people get back on their feet and help the community."
Victim Support area manager Paula Connolly said the ongoing nature of some cases meant volunteers might provide support over an extended period.
"Sometimes a volunteer can be involved in a very serious case and it's ongoing ... and that then becomes a big load when more serious cases happen.
"The team will pick up work that's required in the short term - but in the long term we want to increase numbers."
Current volunteers are from a variety of backgrounds such as nursing, teaching, the courts and emergency services.
The organisation focuses on serious crime or trauma such as homicide, suicide, grievous assaults, kidnapping, civil defence emergencies, and search and rescue events.
Last week, Wairarapa Victim Support volunteers received 12 assignments, including a home invasion, a car crash, a burglary, a sudden death and a serious assault.