Mrs Marshall has just started in the job, which was vacant for about four months.
Her husband Lieutenant-commander Ian Marshall is the Royal New Zealand Navy's resident naval officer based at HMNZS Toroa.
Mrs Marshall said she could relate to families of ex-service personnel as Lt-cmdr Marshall had completed deployments to Afghanistan and Korea.
A former New Zealand Post worker, she saw the welfare officer position advertised and decided a career change was in order.
"It's completely new, but it's all very exciting. I'm looking forward to the challenge," she said.
Mrs Marshall will help ex-service personnel and their relatives with "anything they might need", such as applying for war pensions or dealing with Work and Income New Zealand.
The trust was established to ensure no ex-serviceman or woman suffered undue hardship.
