Here is my $.02....my best friend and I have been best friends for 20 years. She offered me a cookie in Biz Law class in the 10th grade and we've been like sisters ever since. :)
After college we did the singles thing together every weekend. I met my husband first. I remember when I was dating him she had feelings much like you described above. And while the time I spent with her and other friends cut down drastically - the reality is that I was falling in love and wanted to spend so much time with my hubby. Needless to say, our friendship changed a bit and she spent more time with other single friends as my relationship progressed with my husband. Then two years ago she met the man she would marry...we started 'double dating' and became quite close again. She just delivered her first baby (7 weeks after I delivered mine) and our bond has never been stronger.
My point - relationships change and can even fade in and out. Cut her some slack (right or wrong) as she is in a different phase of her life than you are. I doubt she loves you any less.
Good luck, I am sure you miss her as I know my friend missed me. Looking back I know I hurt her by not being there for her - thank God our friendship weathered that.