Seems the family had some significant things going on in 2011. Oldest son got married in August 2011, per the family business website:
http://www.parsonskennel.com/meet-our-family.html
Son number two had an "episode" the same month:
http://www.wsoctv.com/news/news/local/court-records-several-calls-help-made-home-missing/nZJSZ/
Trying to say this gently and keeping in terms of TOS. Mods, please remove if you need to. All MOO...
Maybe oldest son was a protector of sorts, he joined the military, got married and probably moved out of the house, all in 2011. Once that protector was out of the household, something happened to Erica and the family is trying to cover up for the person responsible. Now two years later, the party who is responsible is feeling guilty and, therefore, reported her disappearance to the police. This is just one theory.
Other big red flags to me: The thought of dropping off a 13 year old girl to a distant relative of the birth mother, without really knowing the person/people or where she was going? The birth mother was in Salisbury but is now in Louisiana?