umm unless fang is the size of Godzilla or bigger then she would not have a jaw the size of a Megalodon just look at that link and u will see if she did have a bite mark the size of a Megalodon then there would be nothing left of the guards lol 

http://www.thehistoryblog.com/wp-content/uploads/2011/03/largest-Megalodon-jaw-fossil.jpg