Up vote this discussion if you think Hawaiian should be a duolingo course!
a hui hou no ka manawa,
Hi Kate, and welcome to Duolingo! There is a handy discussion here about what to do if you want a new language course to be added: https://www.duolingo.com/comment/15014194. The instructions basically say to search the appropriate forum for the language name, and if there is already a discussion for it, upvote that and add your thoughts there instead of creating a new one. I did some searching for you and found this one, so maybe you can contribute to the discussion there: https://www.duolingo.com/comment/8224753