You may not like what I'm about to say, but the problem may not be your boss, but you. As you indicated in your second post, she "seems" to favor other people, and you perceive her behavior as "rude". She may not be either in reality - you are simply perceiving her behavior and interpreting this as such.
I recalled working someplace when I was new and was warned about how horrible a couple of the female managers/analysts were in an area I was schedule to work in - and when I got there, I found out the rumors were untrue. The reality in my situation was that both women were strong, opinionated and smart - neither appreciated people wasting their time, and they were very focused on getting their jobs done with an extremely high standard. If they were men, people would have considered their behavior "normal", but because they were women, this behavior was perceived as "mean".
All I did was treated both with respect, was honest and direct with them. I took their behavior toward me as them being straight-up honest and direct, no hidden agendas - and used their feedback to learn the system as quickly as I could, and improve my performance. We are now the best of work friends - and have accomplished much together. Basically through my own hard work, I earned their respect.
One thing to keep in mind also, your boss is not your "friend". Some may become your friends after a while, but in general, their job is to ensure the people they are responsible for managing are doing their work toward the common goal of the company. You may not always agree on their methods, but observe if their motivation appears to be attempting to fulfill this duty - if so, try to learn not to take their behavior personally - just accept it as their "style" of managing. If they ask for feedback, ask if you can be honest and provide almost a scientific analysis of how their managing style is being perceived (don't tell them they are "rude", instead, be more specific in citing an incident where you felt they were rude and explain what about the encounter made you perceive it as "rude" - was it their voice, speech patterns, body language, etc...).
Since it sounds like you are new, observe the people she seems to be "nicer" to - is it simply she appears to be less direct with them, are they high performance workers? If so, try to learn from them how to become as good at the job as they are - by doing that, you may earn your boss' respect and she may not be as "rude" to you.
As one mentioned above, observe her behavior as objectively as possible - try not to tie any outlying meaning to her interactions with you outside of believing she's trying to help you learn your job and be your best. When you start catching on, see if her behavior seems less "rude".
Sometimes by changing how you react to people, you no longer see them as "mean" or "rude", and you find it easier to get your job done. When you thing someone is "mean" or "rude", human nature tends to react negatively back which makes the situation worse. If you choose to interpret their behavior as simply being no-nonsense and direct, you will change your behavior and reaction to work harder and in many cases end up improving the situation by earning their respect.
Good luck!