Yeeaahh she's not sure this is going to go well. Might as well try, though.

"Hi, um. I'm really, really sorry about what happened, my roommate- uh. I don't know what she was thinking." She hurriedly tucks a strand of hair behind her ear, looking torn between staying where se is and bolting then and there. "I'm sure she'll want to apologize herself later, but she's kind of... not entirely functional right now."