Should I keep an eye on her?

I met my bf on the internet game and after 1 1/2 year of daily facetime chat and a 2 week vacation, I moved in with him and we've been living together for over 1/2 year now. Things are going fine (can't avoid little bruise and bumps...its life anyway), but most of his female friends make me feel real uneasy. You can tell just by the look that they previously have sexual connections and these women don't lead a normal, healthy life. They don't even work to earn, but rely on government support and offers from other. He cut ties with them after I gently expressed my concern, which is truly reassuring for me. However, there is one woman that he refused to delete from the contact list. She is one of the gamer from the internet game that my bf and I met, and he once said that she is the "dream that never come true" in his life. They are living in a distance that they will never really able to meet. However, the way she talked to him was so bizarre that disturb not only me but other people in the game. She openly flirt with him, sharing the fantasies she wrote with him and her on the blog, and even talk about how she dislike the look of her vagina and therefore they never had sex during the good old time. The most disturbing fact is she said all these, after telling everyone that she is married and have 4 children with the husband. She knew about our relationship and she seems to be "happy" for us. However, everytime she has a chance, she will talk in a way that she still deeply fond of him, and bossy around every action or decisions we made. When she talked to me she always have that superior tone of she knew him more than I do, and she will help to fix him if I cant handle him. Her actions irritate me a lot and I just want her to be out of our life. However judging on my bf's action she will still be around virtually, until she seriously across the line and I erupt. My bf's been loyal to me and I know that they will never really have the chance to meet with each other or having any physical contact. Maybe I should not be so wary about her. But should I keep an eye on her?