Oops. This is it:
http://www.morganhorse.com/
There should be contact info. for the club and she could always call.
It all depends on what she's wanting the registry for. If it's just to certify the pedigree, fine. If she's wanting to compete, it all depends on what she's wanting to compete in as far as what titles are recognized by who.
A little more difficult than the dog world, but not by much.