<human>: Can you summarize the given text in a few sentences?

She is the friend of my friend (they both moved in together with me two months ago) and she is incredibly sensitive. She is also a total know-it-all and has to be right about every topic, all of the time. She regularly corrects my grammar and tells me that I'm wrong about one thing or another. She also refuses to speak about what is really bothering her and instead chooses to hide behind self-diagnosed excuses ("I have insomnia and bi-polar disorder and depression."). And today I get this, "I feel the soft anticipation of a confrontation I won't make." on facebook. She is 23 and this is her first time out on her own. I get that she's still in a high-school mindset but I moved out when I was 18 and I'm not ready to regress three years.
<bot>: I have a roommate that acts like she's still a moody high school-er and I don't know how to deal with her shit. What do I do?