Eddie,
How old is your sister? You (she) may be able to do what she wants just all with tile scripting.
She's eleven and quite advanced for her age. She skipped ahead to 7th grade this year and still manages nearly straight A's. Consequently she's gone from pre-algebra to algebra in one swift step. She's having trouble breaking the equations into small steps and doing them sequentially. I think teaching her some basic programming will be a fun way to help her.
I think I'll start with tile scripting and if she shows interest I'll begin showing her how to write the actual code. At the very least I want her to learn sequence, selection and repetition.
Sounds like a good idea. EToys' expressive power is indeed limited, but you can do pretty impressive things in eToys, definitely more than a programmer in a typical language would imagine from the first look how much it can.
The Holder can hold many objects and has a cursor. So these are good basis for the sequence. The "ticking" does provide basic repetition. If you put a small differential in a script and tick it, you can effectively integrate the differentials. This is pretty powerful idea.
You might want to join squeakland mailing list for more discussions on the tile programming in eToys.
http://squeakland.org/mailman/listinfo/squeakland
-- Yoshiki