Who is Heidi?

I am still trying to figure out who exactly Heidi is and what her relation to this case is.  She seems to be a friend of the family and someone that Genevieve trusted.  Perhaps Heidi holds more answers.

In an effort to bring more clarity to this case, I have gone back through all of the documents that have been uncovered.  I am looking for any sort of pattern or any clues we may have over looked.  I feel like there is a lot of information out there.  It's just a matter of putting together all of the pieces.

• First there were the three password protected documents that were cracked.

• The first was a diary entry written by Genevieve making a direct reference to the necklace that started this whole search
• The second was a newspaper article about a business merger between the fathers of Genevieve and Charles
• The third was fire arm bill of sale indicating that Charles had purchased a gun

• Next was the postcard from Genevieve to her mother proclaiming her unhappiness
• The sections of the seal eventually formed a full picture with a hidden web address revealing an unused plane in Genevieve's name from New York to Paris dated two weeks after Genevieve's disaperance
• There was then an article about Genevieve speaking to a group of young school children and an associated video with a bunch of weird numbers
• Next was a map of Trinity's campus with different parking lots circled
• There was the deposit slip that showed that Genevieve had deposited $15,000 to a bank in Moulton, TX
• There was what appeared to be a piece of a newspaper article that surfaced
• And most recently we have the letters between Genevieve's mom and Heidi

Based on all of this information, I have formulated three possible theories:

1. Genevieve, unhappy in her marriage, ran away, perhaps on her own accord or perhaps with the aid of someone else
2. Charles, after finding out about his wife's unhappiness, snapped and killed her
3. Genevieve's father killed her and covered it up in an effort to protect his business venture with Charles's father

I feel like we are only a couple pieces away from solving this case.  Keep your eyes open.  It is more imperative now than ever.