My cousin is terrible?

So a little back story (sorry this will probably be long). My cousin is 7 years old, one of 6 kids in the family. Her and all the siblings are adopted. They have their share of issues stemming from genetics and circumstances. Her mom and dad (my aunt and uncle) are going through a divorce. So with all that in mind I understand she probably has some underlying issues. However, my cousin has also never been punished. She has been in their household since she was 5 days old. I should also mention that my mom and sisters lived with them for years, so my cousins are like my brothers and sisters. Still, she scares me. She has legitimately stabbed me in the arm with a pencil (when I was just laying on the couch doing nothing) with no reprucussions. She throws dangerous tantrums where she breaks, or threatens to break things every time. She says she is going to kill you almost every time. She punches, kicks, bites, spits on, or her favorite, digging her claws into your arm until you bleed. She is out of control. That being said I am scared to be pregnant around her. I am scared she will punch me or kick me in the stomach and I'll lose my baby. I'm worried when I have the baby, she will get mad and throw him/her which is obviously terrible. I don't want her to be allowed to hold my baby. However I am also worried about the fall out with my aunt if I show that I don't trust her. I seriously need help. How would you handle this??