In reply to John Kelly:
I saw this a while ago; the description made me laugh:
http://www.braemarmountainsports.com/index.php?main_page=product_info&c...
I would suggest any of the lighter-weight frame binding e.g. Fritschi eagle; these generally come in 2 or 3 sizes - even the small size will accommodate a reasonable boot-length range. and a couple of changes in boot size.
you'll need to get an idea of how shoe size translates to mondo size and boot-sole length.
the light weight stuff will be fine (without obsessing over weight).
for skis: any lighter-weight narrow (relatively) ski should be ok.
again don;t obsess over weight - and don't think that you need >90mm width.
(any discussion over fatty skis really should rest on how much deep powder are you really going to ski)
boots - whatever is cheap and functional.
an 11 yo'ds feet arn't going to stay the same size for very long........
(but I'm sure you already knew that)
have you tried hiring ski touring kit already?
you might be able to get away with hiring boots for a wee bit