[Gorgias]

She might be able to use CodeSkulptor.org

It was designed by a Rice University professor and has some very useful features for the classroom. Mainly that they can turn in their code just by sending the URL. It has a few idiosyncrasies but it is a very friendly environment for learning in.

[pajop]

also:

http://ideone.com/ http://codepad.org/ or even http://www.codecademy.com/tracks/python

[aethertron]

Here's another one: http://repl.it/

[StevenXC]

Thanks for the link! (And thanks to the others below for their links as well!)