Shared folder subfolder inherited rights

I have an interesting problem. On my home computer,
running Windows XP Pro, I have multiple accounts for
everyone in my family. Daughter #1 creates mp3 files
(legally!) in the Music folder in Shared folders. She
does so by creating a subfolder (e.g. Movie Soundtracks),
a subfolder under that called Chicago, and then the actual
mp3's in this folder (Chicago). Daughter 2 (who does not
have admin priv) cannot access these MP3s to play them,
but can "see" them. After much testing, I have determined
that a simple Windows copy from this folder and then back
then allows her access to the file. What did the copy
change to allow her access to the file? They were
originally created using Musicmatch. Any thoughts on how
to correct this w/o giving daughter 2 admin rights?
Daughter 1 has admin priv as Musicmatch requires them.

Thanks