We make it really easy and accessible for people to get started even without having a background.
We've had students aged 9 (http://blog.codehs.com/post/39684965497/9-years-old-and-codi...)
to 85 (http://blog.codehs.com/post/37288742720/im-85-and-i-learned-...)
We focus on teaching the fundamentals of thinking like a programmer, so even though the site is based in JavaScript, she'll be able to apply her knowledge towards matlab.
Also, it's really fun, and if she continues, she will learn to make a mobile game or two along the way.
You can email me at zach@codehs.com if you or she have any questions. Or just sign up for the free trial to check it out.
We give personal feedback to all of our students on all the code they submit, so they're sure to improve and not only write functional code, but code with good style.