One clue is in the library the other is in the locked room that you need the Emerald key to open
There is a book you click on in the library that will tell what kind of code it is, then there is the parchment you can get in the locked room which has a strange word on it. Taken together you should be able to work it out from there.
Comments
I WILL say however, that due to the robe you can buy from the sisterhood, you inspired me to create a character named Freya.