Beth, I agree. Its cool to use engineering to solve old and new problems. Its also important to maintain a creative mindset through imagination foster by fairytales. Also, the problem illustrates that not only men are good engineers but women as well. This problem should be presented to the Myth Busters to validate the math behind the solution.
Fun example and certainly one that could and should be used to encourage interest in STEM among girls. While the math may play out, I like your mom's version that the slippers were magic. Afterall, some fairy tales are better left to just that--fairy tales.
At this year's MD&M West show, lots of material suppliers are talking about new formulations for wearables and things that stick to the skin, whether it's adhesives, wound dressings, skin patches and other drug delivery devices, or medical electronics.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.