where is a restricted user's home directory for Nexus 7 (2013 - JB 4.3)
They are stored in 

/mnt/shell/emulated/


I've just created a restricted profile and it created a new folder in there with the name "10", the main admin users folder is "0". You should be able to copy the files into the relevant place within these folders to get mine craft to pick them up.

(This was done on the 2012 Nexus 7 but I don't think it will be any different)