Look in the America Online\organize folder for a series of files named after your daughter's screen name. On my wife's machine they are:
C:\Program Files\America Online\organize\screenname (note: no extension)
C:\Program Files\America Online\organize\screenname.abi
C:\Program Files\America Online\organize\screenname.aby
C:\Program Files\America Online\organize\screenname.ARL
C:\Program Files\America Online\organize\screenname.BAG
C:\Program Files\America Online\organize\screenname.AUT
Don't forget the files in the C:\Program Files\America Online\downloads folder.
If you are planning on migrating your daughter's AOL install to another drive your best bet (read "what I've done in the past") would be to copy the entire existing AOL folder to the new drive. Then, install another copy of AOL on the same drive and tell it you want to upgrade an existing version of AOL (even if it is the same version). The installer will locate the existing installation and offer to either copy or move all the existing files (including the mail store) to the new installation. Copy it, then have your daughter use AOL for a few days. If everything seems OK you can then delete the old AOL folder and all its contents.
This has worked for me, YMMV.