Mom is bothered I'm more liberal?

 I'm 20 going on 21. My parents are both republican so of course that's how I grew up. It wasn't until about 2 years ago I started realizing I agree with more liberal/Green Party politics. I'm shocked my mom hadn't figured it out sooner! Well she noticed my postings on facebook and made it clear she didn't agree with them. I just said okay, because we can have different views. But she seemed irritated and told me to be "open minded". I'm an adult and she expects me to still follow her beliefs. This makes me want to move out quicker especially if she's going to stalk my facebook and yell at me about them. What are your thoughts/advice? :/