If you want to rekindle the friendship, then it's up to you to make the first move. Get in touch with her. Tell her you're sorry and offer to make amends. Ask her what you could do to improve the relationship. Two things though: 1) I know I make it sound easy to reach out but I know it isn't. It involves swallowing your pride. and 2) Are you prepared for the possibility that she won't be interested in reconciling? If things don't work out, at least by getting in touch with her and discussing things (if she is willing) then you will get some closure. So many times friends will just abruptly stop calling and when I try to get a response, then never get one; it leaves me wondering what happened. A simple "I don't want to be friends anymore because..." would go a long way. Who knows? After you make contact, you may decide that the friendship has run its course. Just keep an open mind.
Believe me, as a shy, introverted person, I know what it's like to have a friend drift away. An extroverted person likely has many friends thus if a friendship dissolves, it doesn't hit them as hard.