Can sisters be sponsors for the student visa, or is it better to show parents or husband as sponsors in New Zealand?

Yes, your sister can sponsor your New Zealand student visa application if she is a New Zealand citizen or resident.

Immigration New Zealand accepts sponsorship from immediate family members, including parents, siblings, and spouses. However, sponsors who are parents, spouses, or siblings living in New Zealand are generally preferred due to their closer financial ties and responsibilities.

If your sister meets the residency and financial requirements, she can sponsor you. Otherwise, showing parents or husband as sponsors may be stronger.