The volcano at the centre of Ambae Island continues to erupt, smothering the island in ash that is killing crops and making breathing difficult.
In a repeat of last year's mass evacuation, people are now being herded onto ships to flee to other islands but this time it seems they will not return.
The government ordered the mandatory evacuation last month and declared a state of emergency after the ash fall intensified.
The International Planned Parenthood Federation's Nerida Williams was with a boatload of evacuees as they were taken to the nearby island of Maewo last weekend.
"People love their island and it's their home and they wish to live there but there was also, I think, a level of acceptance that the time had come, that they needed to go," Ms Williams said.
"It was becoming quite untenable to remain there at least for the time being. And then once that decision was made, I think it was an acceptance."
Some women had reported feeling vulnerable in the tumult of the evacuation, Ms Williams said.
"We spoke to women who were feeling a lot more unsafe because there were so fewer people on the island now," she said.
"Families are being separated as they move to different islands, and so women were feeling unsafe not having the usual protection mechanisms around them."
The federation and local organisations had been running support clinics with evacuees, the aid worker said.
More women had opted to take long-term contraception since the volcano started erupting, she said.