You can restrict access by first having the drive automatically mount on bootup. Go into "Configure your Computer" -> Local Disks -> Manage.
Click on the partition with your files on it and then click on "Mount Point", name your mount point /media/windows (or /media/whateveryouwant). Click on Mount. Click on Done, and if it asks if you want to save fstab modifications click on OK. You can now close the control panel.
Now open up the console and your mount point should appear in fstab (which is the file that decides what partitions automatically mount). Typically, there will be a line in there that says umask=000 which gives all users read-write-execute permissions (and you dont want the girl to write, obviously). So we're going to change that by assigning an owner to it, and only giving that owner RWX (read write execute) permissions, while everyone else just gets RX (read execute) permissions. So lets modify that.
First of all open /etc/fstab as root (so you can edit it). In the portion of /etc/fstab, find umask=000 and replace it with umask=033,uid=YOURUSERNAME,gid=YOURUSERNAME.
Replace YOURUSERNAME, with the username of the person who you want to assign as the owner (if you're unsure what your 'username' is, open the command prompt as the user who you want to assign as owner and type "echo $USER" to find out). Save the file. Reboot.
Now the when the kid logs in as her own user name, she will see the disk and be able to view its contents, but will not be able to write to it.
