So...my theory on this that will prob NOT be true but just something I was thinking about
: I feel like they are 'getting rid' or going to kill most of the family she has...that way if and when Elena turns into a vampire in the future of the show it won't be seen as selfish or have that 'Bella-effect' to it (how she kind of just left her parents to become a vamp). Like i said not saying this is likely but it's my theory on it