I Need Advice

My first cousin and I grew up together. We're like sisters and we talk almost every day. I called her a couple of days and she told me that she was 5 months pregnant and she just found out last week. She's 18, just finished her first year of college, and now she's back living with her parents. She went 5 months without a cycle and didn't think that something was off. So I ask her what's her plan. She says she wants an abortion. I'm like okay fine. Then she went on to tell me that she bought some abortion pills on the internet and she doesn't plan on telling her parents. Then she begs me not to tell anyone. I don't want her taking those pills so I begged her to go to clinic. She won't go. She got so mad at me when I gave my opinion. So I'm faced with a dilemma. Do I just go ahead and tell her parents? Or do I just let her do what she wants?

UPDATE: I told my mom who went and told my cousin's mom. My cousin told her parents that she was raped. Her parents immediately knew that she was lying but... I can't believe that she would say something like that.