I am trying to find a good summer program for 2017. I am a rising junior and am very interested in STEM, particularly engineering and computer science. I need a back-up if I don’t get accepted into Girls Who Code.
you should look into mit’s women’s technology program 
http://wtp.mit.edu/
stanford,mit,caltech,carnegie mellon
look it up there! 
Women’s Technology Program is only for rising seniors. I did Girls Who Code last summer, so if you want, you can ask me questions about it.
Here’s a (quite) extensive list of science-related summer camps: http://cty.jhu.edu/imagine/resources/summer_programs/science.html