The advice given has been excellent. We would suggest that since the listings are the possession of the Broker that your desire to be released from your contractual obligation be directed to the Broker. He/she would be able to authorize termination of the contract.
Have her do another market analysis and see what she comes up with. I also suggest having open houses at least 2 times per month to satisfy her work for your needs, and also make sure you are on every website possible. Is your home in the Real Estate Book, Realtor.com, there company website, her personal website, homeseekers.com, lycos.com, craigslist.com, truilia.com, as these are all free sites she can list your home on. You should contact your realtor at least once a week by email and keep in touch with whats going on in the market. Good luck and I hope you get it sold, and if you have had a number of showings, your realtor has done her job marketing it to other realtors which is her duty also, so look at your price, which is the ultimate for selling your home. Best of luck to you!
And yes, you should be told of any showings.
How did you find her? If it was a referral tell the person who referred her so they don't refer anyone else to her. If I made a referral and the agent didn't perform properly I sure would want to know.
If it was a 6 month listing you might be better off to let it run out then find someone else. (By the way that would not be me because although I work in your area it is only for people buying homes - not selling). I can, though, research agent histories for the area and likely find someone good for you.
If you are also buying, I am an EXCLUSIVE buyer agent. That means I work in an office that does not accept listing due to the conflicts of interest.