August Rush?

So I have heard several different things about Kaki's involvement with the film, and I was wondering if someone could clear this up for me? I heard that she played some of the songs for the soundtrack, wrote some of the songs, and did August's fingers playing the guitar when the camera was not focused on his face. On IMDB she is credited for writing Bari Improv, and for performing that and Ritual Dance, but is that just on the soundtrack? Or are those her hands playing? Or what?

Thanks! Sorry that the questions were poorly worded.

She wrote Bari Improv and did a Cover "ala Preston Reed" of Michael Hedge's Ritual Dance,
and the actual hands on the movie anr hers excepr when you see Freddie Highmore playing..