I'm so sorry to hear that this happened to you. But let me point something out to you... if she is bothering you that much, you need to block her and whoever else you wish to block. So what if she and her clan call you and your clan "weak" and "easy"? That doesn't mean it's true now does it? Since when did their word become law?
They can't really kill you, or you clan members. It's just a roleplay game. No one can really die in the world of Feral Heart. The only way they can is if the owner of the character chooses to have their character die or be killed. Other than that, Deathstar isn't the one who decides which characters die, who gets hurt, what clan is weak, and so on. She really doesn't have a say in it.
If things really get out of hand, take some screenshots and send them in a private message report to a moderator. That's the best you can do. If you don't want them harrassing you and your clan, I would suggest blocking them.