Invasive, or am I just an all around kind of snob?

I have a roommate that is irrefutably intrusive and I am not overemphasizing. Yesterday evening, my son and I were having a conversation and my roommate barged through the door about a million times. No knock. No hello are you in there. No I'm sorry did I interrupted anything. No nothing of that sort. The first time she rudely waltz in, she asked my son a question, disregarding the fact that we were talking. After he answered her, she closed the door and stood there... like, standing there to eavesdrop. Me and my son looked at each other and whispered to each other, "is she trying to listen to us?". We didn't speak until we heard her door close. Then again, she barged in while we were talking, and again she asks my son another question... with a cup of milk in her hand, she asks, "do you want some milk?". My son say's no, with a fallacious look on her face she say's, "okay" and walks out. I look at my son and we both roll our eyes. Long story short, she repeatedly barged in at least another 4- 5 times, not to mention, she knocks on my door early in the morning as if she really needs to ask me questions like: "do you want an omelette, do you have clothes in the washer, do you have some money I can borrow, are you up, do you have milk?". I mean, the list goes on and on. On top of it, when I do lock my door and if I avoid answering her, she is overly persistent and knocks a little harder and speaks a little bit louder each time she hears nothing after I have ignored her on purpose. It is hard for me to fathom that thought of me sleeping does not cross her mind. How can I help her understand that she is obsessing? She doesn't do well with me being upfront with her. She is very impulsive and her erratic behaviour is driving me insane. This broad is too much.