I found a very interesting site where you can read:
"Despite the great number of organ schools, there has never been a
beginner ' s pedagogy/methodology for children. For the first time it
is now possible for children to learn to play the organ using the
Suzukimethod."
In this site you can see some videos of children playing the organ.
http://www.organsuzuki.com/
They start studying organ without a previous knowledge of piano.
I will adapt some of these ideas here in Brasil.
Best regards,
Miriam