A student from Hawaii? A student of the Hawaiian language? Or both?
I would consider that to be a student from Hawai'i/student of Hawaiian descent. A student of the language I would add the word for "language" in there.
"He haumāna ʻōlelo Hawaiʻi au"?
aloha e koma mai
How would one designate whether they were a student who was Hawaiian, a student studying Hawaiian or an American student born in Hawaii (like Obama).