Have a think about it and decide whether she is the kind of girl you like, and if you can, try and get to know her a bit more. A month or so isn't much time to get to know the in and outs of someones personality in my opinion, but you may think otherwise. Once you have had a think, swallow your fear and just talk to her, but obviously at an appropriate time. Or, if you really don't have the balls to tell her straight, then just ask her out. For example, ask her if she would like to go for a nice Dinner and a movie. You don't need to hint that it's a date, as she will eventually realize that you are attempting to make it a date, and not just a normal day out for you guys.
Even though I have been with the same Girl for 7 years now and we are comfortable enough to do anything or say anything to each other, there have still been times when I have wanted to say something (Not always something to do with my love for her.) but didn't have the courage to do so. When I do eventually spit it out, she wonders why on earth I didn't want to say it earlier.
A bit of a pointless thing to tell you I know, but my point is just talk to her. Too many times I have heard stories from Friends (Be it Male or Female) who have really wanted to tell someone they have an interest in the other person, only for that same person to not realize and go off with another guy or girl.
And one more point, don't be scared! If she is a true friend but didn't have no interest in a relationship with you, then you telling her you have feelings for her should not affect the friendship in any way. It may provide some awkwardness for the first few days after, but that will soon wear off and you will both be back to normal.