The island was evacuated when a volcano erupted in September, and communities are now returning to food and water shortages.
But the foundation's Nerida Williams, who has just been on Ambae with a team of doctors, said the need for sexual and reproductive health was also a concern.
She said rates of STIs and HIV often spiked in times of emergency, and pregnant women and infants were put through traumatic encounters, which can have a detrimental effect.