Should I cut her (my younger sister) off for good?

In a nutshell, I've been the good exampled big brother, never abusive, condescending, or berating. But things change as we get older, since my fathers death in "92", my sister developed a selfish streak that's only gotten wider and longer with age. The gym is her obsession, even when she visits family or friends, I gave her away at her wedding last april, and when I took a road trip last month by her neck of the woods, she made it so uncomfortable to see her that I byped her both going and and coming home. She has yet to apologize without twisting the scenario of guilt towards me, and I've just about had it. My mother thinks I'm being over sensitive, but even my best friend who accompanied me on the road trip was mortified. I'm actually at the point where cutting her off is an option.