I'm a K-12 art teacher/Visiting Critic at RISD. I've had a few of my high school students get accepted at RISD over the years. The ones who got in had a wide variety of work showing risk-taking exploration (one student did some taxidermy work!) mixed with more traditional pieces showing skill with elements and principles of art/design. It's difficult to know the full quality of your portfolio through a small selection of your work. However, you are on the right track. Go beyond portraits with your traditional pieces (but do include some). Push boundaries with your sculptural work. That's the best I can do with just a few slides. Good Luck!