Not a big fan of the action script style syntax really. The few times I've tried haxe I've had some issues compiling to various targets. Couldn't get some of them to work for the life of me. Though, that was when I was on Win8 and VS2012 dev previews. There were some conflicts with the beta sdks. Not really haxe's fault. I haven't tried haxe since though.
I'd like to keep the workflow as simple as possible. I don't want to have something mess up causing me to spend a bunch of time trying to fix it while she just sits there. I don't want to scare her away thinking it's too hard or get confused by me doing advanced stuff that's not really relevant to what she's learning.
haXe is also statically typed. I know many claim statically typed languages are better and easier to debug, but I've read a few studies that have shown the opposite for the complete beginner. They were slightly faster at coding and debugging problems with a dynamically typed language.