Any advice would be pretty chill

It seems like you don't know her too well. If that's the case, since you are going to be spending a lot of time around her the best thing to do would be to just get to know her. I've been scared of people several times before, but once I got to know them everything was fine. If that's not possible or she really doesn't like you, what I always did was have a friend or nice acquaintance be near me at all times just in case. OR if you are good friends with someone that is friends with her, she'll be nice to you by default because she won't want to upset your mutual friend :) Haha

I came on here intending to talk but Marisa stole the words from my mouth. It's perfectly normal to be afraid of someone for no reason. I do it, people I know do it. The best solution is to get rid of this foreign fright. If you're afraid of a closet in your room it most helps to open it and realize there are only coats and mittens inside. Of course, the process of opening the closet is frightening. You have no idea what's inside and you don't know how to handle it.
My advice is to talk to this girl. Since you're quiet you can start subtle. Say good morning or hello to her when you walk by, smile when you make eye contact. Treat her with friendliness and when you reach the point when you can have a conversation, you will realize that she is not that scary after all. Maybe you two will bond over a book you both like or maybe that conversation will be it. You'll talk, you'll separate, and you'll see that she's just a normal human with feelings too. She could be really nice and you'll wonder why you ever thought she would judge you. Congrats on the part and good luck!