First of all, if this it typical behavior for her then everyone knows it. You said yourself that there is this chain of "best friends" she has ditched, so there are at least two other character witnesses for you. Second, if she is engaging in this type of destructive and hurtful behavior, why not bring it to the attention of your personnel chair or an advisor who can maybe investigate and take her aside on this. It doesn't sound like she is adding anything positive to your chapter. Save her emails if she sends any more so you have examples of her nastiness to show if necessary. Continue to be yourself and don't let her bring you to her level. One person should not be able to ruin your chances if you really fit the position. Good luck!
