"Her aunty is a short woman."
Translation:He wahine pōkole kona ʻanakē.
I'm not entirely sure, but what I've noticed is that sentences that describe something with an adjective (e.g. "his mom is nice," nice being the adjective describing the mom) don't need "He" in the beginning. So this would be "ʻOluʻolu kona makuahine." If a sentence uses a noun to describe something, then you would use "He." For example, in "Her grandmother is a Hawaiian," "a Hawaiian" is a noun, so you would say "He Hawaiʻi kona tūtū wahine." Or "That teacher is a short woman," "woman" is noun descrbing the teacher, so you would say "He wahine pōkole kēlā kumu."
The only thing I'm still not sure about is where the determiners "ke"/"ka"/"kēia"/"kēlā"/kēnā" would go in the sentences.