Similiar thing happened to me a long time ago. She was a cousin of my ex-girlfriend - better looking than the ex.
A year after the breakup I ran into the cousin - we started seeing each other as friends - movies, dinner, xmas parties, company picnics, the whole nine yards. She was always talking about some guy she was dating (not really dating, the guy was just banging her). She knew I wanted more, but it never happened, she just didn't see me in that light.
The thing that pissed me off was that in front of other people, she acted like we were a couple, but alone, it was a different story. I had enough and just stopped calling her. That my advice to you, stop calling her, if she interested, she will let you know. If not, you saved yourself a lot of trouble.
BTW - nobody is out of anybody's league. I'm a pretty average looking guy, married an ex-model - so ya never know.