My understanding is that marine biology is an area where you need a graduate degree. You have a very good program at your local university which is very affordable.
I also really like the option of taking a semester or a year abroad. One of my daughters did this in high school, loved it and did well, and doing something similar in university seems just as good if not in many ways better.
If your daughter wanted to go on to a very highly ranked graduate school as a graduate from the University of Hawaii, then she would need to be one of the top undergraduate students at the U of H, with strong grades and strong references. However, this sounds entirely possible, and even highly likely to happen.
As such this looks easy at least to me: IMHO she should attend U of H, work hard and get very good grades. She should very seriously consider taking a semester or a year abroad (whether in Australia or elsewhere). Then she should look for a higher ranked university with a strong program in her major for graduate school.
One thing that I wonder about: Here in the “connected 48” states, and in particular living in New England where there are a huge number of universities nearby, it is normal for high school seniors to apply to 6 or 8 or 10 universities. One friend of a daughter applied to 25. Do high school students in Hawaii normally apply to a very small number of universities, simply because there aren’t very many that are nearby?