Ask HN: Fun ways to learn Javascript for a 12 year old beginner?

My 12 y/o niece started off playing with HTML a while ago, and then worked her way up to a bit of rudimentary copy+paste+tinker Javascript coding. I'm looking for fun tutorials/frameworks/etc. to show her, so that she can build cool stuff and get the hang of coding. I'd like to introduce her to processing.js, but I can't find tutorials (their learning section just seems to have demos sans explanation or how-to). Once she gets a bit more comfortable I'd like to introduce her to a bit of game stuff (maybe via LOVE or PyGame) and then some other coding so she can do simple web programming (node.js? PHP? Python?). So, any recommendations on any of the above? What do I start with and where do I go from here? PS. I find Squeak a HORRIBLE environment and really quite unintuitive, so that's probably out -- unless you've got some compelling tutorial/package that makes it otherwise. Thanks so much!!