How can I confront someone without creating any drama? Is it possible?

I am a naturally non-confrontational individual. I've honestly never been the slightest bit angry with someone until now. This person, Beth hangs out with people whom society would generally consider to be on a higher social ladder than myself. While I interact very well with them (as I am a fairly easy-going person) Beth constantly undermines me around these sorts of people. This would not be such a big deal if she were just the usual snob, but Beth actually used to be a part of my own social group -- now she parties, and is now "cool." In the process, she's rejected her old social group, and thinks she's become better than them, than me. She constantly tries to pressure me into becoming who she now is, but it's simply not going to happen. I know who I am and want to become -- she's not going to make a difference. Yet now she accuses me of "dissing her" for the past four years, when the truth is, I've been avoiding her because of all this! How can I enlighten her w/o the drama?