Hearing Her Talk

The girl I've been stuck over is much different from the others. We actually have things in common with each other, yet we a very different people. She is hard driven to succeed, I am not unfortunately. We are pretty much best friends in a sense, yet it has been less than a year since we met. We hit it off right away and I felt really close to her. I wish we were closer than we were now, but she has a boyfriend whom is also one of my friends. Whenever we hang out, I just let her talk. I love hearing her voice, when she's talking about her day or ranting about something that is ******* her off.

We have had those moments of being close, her telling me I am one of her first people to contact in a crisis. That struck me really hard as I didn't expect it. I told her she can call me whenever she needs to, just letting her know I am there for her where ever. It makes me wonder everyday how close I am to her in her mind. I just want to know. I've been told to just tell her how I feel, but I am not sure if that's a good idea at this point (mainly due to her bf), nor have I gotten a good opportunity to do so. Am I really just that best friend? or could I ever be something more?