Ayodeji,

I am not sure if this will really be much of an assist, but this is probably the best you will be able to do when dealing with anything child related as it is very challenging to procure hash sets for anything child related unless you are law enforcement or LE sponsored to perform forensics etc.  You may want to consider speaking with someone at your local ICAC or NCMEC.

You can use the NSRL datasets found at the included link for non-child related hash sets for research projects.

http://www.nsrl.nist.gov/Downloads.htm

You can use Autopsy to perform some of that research.

http://sleuthkit.org/autopsy/docs/user-docs/3.1/hash_db_page.html

Good Luck.